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SOHC.co.uk Forums => CB750 => Topic started by: the-chauffeur on June 09, 2011, 11:30:54 PM

Title: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 09, 2011, 11:30:54 PM: Guys

I'm putting the finishing touches to my K2 rebuild and I'm at the point of fitting the headlight, but I've run into a few snags with the wiring - mainly that I've got more spare unconnected wires than there seems to be space/need for. I'm getting my head round it slowly, but was wondering if anyone else has added one of the left hand mount plastic high beam switches to a K2, and if so, what changes needed to be made to the connections?

Coming out of the RHS switchgear, I've now got the following connectors:

Red/yellow - connect to starter circuit
Black - connect to cut out circuit
Black/white - connects to cut out circuit
Black - connects to lighting circuit
Brown/white - connects to instrument light circuit
Blue - high beam circuit
White - main beam circuit

Yellow?
White/Yellow?

All the diagrams I've seen say there should be 7/8 wires out of the RHS - can't quite understand why I've got 9.

From the high beam switch:

Brown with blue stripe
Black

I have a feeling I may need to undo a few of the existing connections and reroute them, but like I say, I'm struggling a bit. Any advice as to what needs to go where would be great. Oh BTW - I've tested all the other circuits and they work fine (brake lights, tail light, indicators, horn, neutral switch, oil pressure switch). I 'spose that's what's referred to as a good start . . .

And something else that has just occurred to me - the bike is a European spec K2, which means it has a sidelight (for want of a better word). The lights should, therefore, have four positions - off, sidelight, headlight and high beam. Unfortunately, I don't think this is going to be an easy job - with the K2 switchgear, there doesn't seem to be any way to have the main beam and full beam on at the same time - it's one or the other. Guess that's why occasionally everything used to go dark when switching between the two.
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on June 10, 2011, 06:49:43 AM: That RH switch ain't a 500 as they never had yellow or yellow white, i think that was 450

What you can do is fit the 750 round on/off switch and route the power out of that to the dip switch in the headlamp bucket, then leave all the lighting wires in the RH switch disconnected just using the kill and starter.
On/off switch is 35150-300-730, screw is 93500-04016OA
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 10, 2011, 07:38:41 PM: Hey Bryan

Thanks very much for that. You're quite right about the 450 wires - guess I must've mixed up my internals when I put the 750 one back together. Ignoring the white/yellow and yellow wires makes a lot more sense.

I've already got one of those plastic hi-beam switches - that's the bit I was referring to previously. The problem I think I've got now is that I can't run the main and full beams at the same time - which is kinda what I wanted to do. Also, I've got one of the left hand switches that has a passing/flash setting - and combining the wiring for that with the wiring from the RHS confuses me even further.

I might just leave the wiring for now. I fired up the 750 for the first time in about a year earlier on today. It's going to take quite a lot of messing around with to get it to run right, and I've already found a couple of little leaks that are going to require the pipes off. Meantime, I've got another electrical issue - the neutral switch doesn't seem to switch off (I think that's a little unusual). I'm guessing the switch isn't seated properly or the o-ring isn't compressed enough, 'cos the gears engage fine . . .

Any thoughts on that one?

Cheers

BTW - the clutch is noisy as hell; I know it's the clutch 'cos it goes when the lever is pulled in. I'm hoping a carb balance will tone that down.
Title: Re: Rewiring K2 with later high beam switch
Post by: SteveD CB500K0 on June 10, 2011, 07:47:32 PM: Quote from: the-chauffeur on June 10, 2011, 07:38:41 PM
BTW - the clutch is noisy as hell; I know it's the clutch 'cos it goes when the lever is pulled in. I'm hoping a carb balance will tone that down.

Dead cert symptoms for unbalanced carbs.
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on June 11, 2011, 03:01:27 PM: Neutral light on could be trapped wire and why do you want both beams on? Generator can't cope with that
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 12, 2011, 03:06:18 PM: Ah - OK. Don't want to fry the generator, so I'll work out what to do with the wiring later.

I'm pleased to say the neutral switch turned out to be a simple fix - I'd put the little locating plate in upside down. Turned it over, did up the bolt and it pushed the switch further into the mount - which meant that when the drum turned, the ball bearing was depressed far enough to switch the neutral light off.

I'm less pleased to say that whilst trying to get the engine set up yesterday - carb balancing and so on to try and cut the clutch rattle down - it got very hot and started squeaking. Couldn't locate the source of the squeak, and pulled the plugs to make sure it hadn't overheated and/or reduce the danger of it seizing. The engine's undergone a rebore, new gaskets and seals and heavy duty studs, new bearings throughout (plain and ball), new chains, camshaft, valves and all sorts. I also had some 2 stroke oil in the petrol to give the pistons an easy-ish time. And I know from using the kickstart it's got great compression.

So anyways, I had too much oil in the engine - following Hondaman's guidance, I'd filled the oil pump before fitting it and that (in part) threw off my filling calculations. I'm hoping the squeak - and the quick heating up - was caused by oil overfill increasing the crankcase pressures and maybe oil squeaking up past one of the pistons. One of the spark plugs looked more oil-fouled than the others, and since the valve guides and seals were all replaced, that could explain what was going on there. I don't s'pose it helps that I was working on the bike in a sheltered (read warm-ish) garage with little airflow, which wouldn't aid cooling at all. But at least I know oil was getting up into the head - taking two valve caps off it was spitting out.

After draining some oil off, I've run the bike briefly this morning, and it seems to be OK. It's not MOT'd yet, so I can't take it out and ride it around, but I'm hoping to get that rectified later this week. I'm just praying the squeak isn't something more serious - I've just had to overhaul the top end of my 450 because a shop I'd asked to set it up moved 2 of the rocker adjusters too far and the shafts have been running eccentrically in their journal holders. The really worrying thing for me is that the giveaway was that it was squeaking, too . . .

Hoping for some good news.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 15, 2011, 09:37:23 PM: Well, the squeaking noise turned out to be bad news. From cold it seemed quiet . . .

. . . so I got the bike as far as the MOT garage and home again (about 3 miles all round), but about halfway back the bike started protesting - more squeaking and hard running. Just about made it home and it died. Pulled the plugs again and things weren't looking great on #4 so I took the rocker cover off (thank God for the removable frame section over the top of the engine). Long story short, no oil has been getting to top RHS.

Yup, the lack of anything coming out of the oil jet in the head on the RHS has caused the brand new camshaft and cam tower/caps to lunch themselves, burned the rocker faces and caused some wear on the rocker arms. Pardon my language, but #@%$ me, I'm not having any luck with this bike. This is my third attempt to get the engine rebuilt and I went all out to do it properly (pistons/valves/rebore/headwork/allsorts) and spent ages making sure I'd got everything right - only to have it all screwed up by (I'm guessing) a 1mm hole.

The head's still on, so I can't tell whether it's the jet that's failed or something lower down, but I'll get there soon enough. What's more disconcerting is what I'm going to find in the barrels - I'm praying the bores/pistons aren't damaged. Where the RH end has been running dry, it's ground itself up and there's a quantity of fine paste trapped inside the tower footprint; there's also some very small quantities of fine dust outside of the tower, but since there's been no oil circulating down that end, I'm desperately hoping none of it has gone south.

Another (K4 I think) head is on its way with most of the top end bits I need, but I really don't need this now. At least next time (!?!?!) I'll know to build the top end onto the engine while it's in the frame and test the jets before putting the towers on.
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on June 16, 2011, 09:04:54 AM: Hi Niel , that is real bad news, i feel the hurt for you, i am not sure if you remember my post but when i put my F2 together i heard strange noises and so i cut the frame open removed the rocker cover only to find my cam sprocket nuts working themselves loose, anyway when i rectified the problem i also took the opportunity to turn the engine over and check that oil was making its way up to the cam towers , it is something i will always do from now on with my sohc bikes as i have heard so many stories of blocked oil jets,
As you say your luck in rebuilding this engine has been really bad, if you want a second pair of eyes and a bit of assistance remember i am 5 minutes away from you and i can pop round for any support or help you may need,
Dont let it get you down, at the end of the day it will all be worth it and you will look back and laugh at it all or cry at the money side of things

Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on June 17, 2011, 07:15:49 AM: Sorry to hear that mate, i don't got any more towers like the ones you had before but i can find you a "runner" if you need it.
Title: Re: Rewiring K2 with later high beam switch
Post by: kaceyk2 on June 17, 2011, 07:34:03 AM: Got a nice pair of towers should you need. ( of a late K8 and in great shape)
sad to hear this happened to a new built motor, theres a lesson for all here, at the very least blow an airline through the towers with some oil before fitting and check the oil is coming out where it should be?

Guys something else here, I have seen folks on two stroke forums say this as well and it is pure rubbish,
Do not add two stroke oil to fuel to "give things an easy time " It has the opposite effect.

If you water your fuel down with two stroke oil, your still sucking the same amount of air in, but now with LESS fuel, you have just given your newly built motor a weak mixture, which makes it run HOT, this is EXACTLY what you didn't want to be doing. Especially so to a motor that is still tight.

The same applies to newly built two stroke motors, it will make them run Weak and therefore HOtter, and with a newly built motor, bad news.

Suzuki, for instance NEVER had the autolube pump set higher for run in periods, this is just plain wrong, right from straight out of the crate, it was set where it always should be, take a screw out of the left hand carb, when the throttle is opened till the dot shows, it should line up with a marker on the pump.
This is how they came brand new out of the crate.
Two strokes /four strokes the same rule applies: add two stroke oil to the fuel, it will run weak and therefore hotter.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 17, 2011, 04:07:58 PM: Thanks chaps - and special tip o' the hat to KC for the 2-stroke oil warning notes.

Having had a sit-down-and-keep-it-together session, I set to pulling the top end apart to try to trace the blockage. Much to my surprise, it wasn't the jet - that turned out to be fine. With the head off, I cranked the kickstart to pump oil through the oil passageways and found that there was nothing coming up the RHS cylinder stud that feeds the head. Barrels off too - and they're fine in case you were wondering - and stud out, and the blockage turned out to be something (I'm still not entirely sure what) in the crankcase jet that feeds into the RHS stud gap.

Spiked that hole with a long, thin pokey stick and something gave - I'm damn sure I did that to both sides before I started reassembly, but obviously not hard enough - and cranking the kickstart pushed equal amounts of oil through both L and R feed holes. I pumped some cc's though just to make sure it wasn't going to jam up again, and then took the RHS oil gallery cap off so I could have a look along the length of the engine. Nothing obviously amiss there, but just to be sure I made a cleaning out stick from of a long piece of thin threaded rod with a nut on the end, and covered the nut with a small piece of cloth (I needed something that was just wide enough to feed in without touching the sides and pull out again whilst resting on one side to pick up any junk).

Again, nothing too sinister there, so I'm kinda concluding the blockage was a couple of beads of vapour blast media that had stuck together and wouldn't shift; the sharp poke broke the surface tension between them and they fell apart. The gallery was shiny and empty after the rod cleaning, so once the new head turns up, I'll clean and modify the towers, and mount them without any other cam train parts. I'll then use the kickstart again to make sure the oil flow is fine. The only other things I needed for reassembly were a new base gasket, some of the round rubber pucks that go under the cam towers and the teeny-tiny o-rings that go round the jets and blanking holes at each end of the towers. Having rebuilt the engine three times now (don't ask), I had spares knocking about.

Rockers and rocker arms have been polished and I now can't really tell the difference between the ones that were on the RHS and the ones on the LHS - thank God for hardened faces/rods. Looks like the only real damage was to the cam shaft journal and the RHS tower, probably 'cos I ran it for such a short time. Yeah - it could have been much worse (Pete - the same self-removing cam sprocket bolt trouble as yours caused this most recent rebuild; mine cut into the rocker cover and sent metal bits all through the engine . . .).

And I cannot begin to explain just how much time, effort and pain the removable frame section has saved. The ability to remove the top end with the engine in the frame meant that I could pull off some bits, diagnose the trouble, put most of the bits back on, all without having to disassemble half the bike (or scratch the frame in the process. Equally, I can test the oil feed with the kickstart, pump and tank in place; that'd've been a hell of a job out of the frame. Right now, the bike is 95% complete - I only need to add the head components and rocker cover and we're off again. Without any fear of contradiction, that frame mod kit has already more than paid for itself.

Not bad, huh? Didn't exactly turn out nice again, but this time it's much easier than I thought it would be . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on June 17, 2011, 10:53:42 PM: Years back had a man who ground the cam journals round again and machined half round Phosphour Bronze bushes that were pegged into the towers---It is possible so DO NOT bin anything, at some time in the future those bits may be re-used!!!
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 18, 2011, 11:58:53 AM: . . . 3 . . . 2 . . . 1 . . . and we're back in the room.

All done. Everything's buttoned up and I ran the bike this morning to see how we were going - leaving the exhaust valve caps off 1 and 4 to check the flow. Got it started and had a quick look with a torch - yup, got some flow going on there. Stood back to take the choke off and generally admire the handiwork before noticing the oil pressure had charged itself up properly and oil's spraying out of both caps. Don't think I'm gonna have any problems with the valve train being oiled properly . . . having said that, a quick ride has revealed the top is perhaps now oiling a little too well 'cos there's oil coming out of the upper fins. Guess I didn't use enough sealant on the pucks and on the ends of the bolt threads. Still, sorting that out with the top section off should only take about an hour and I'm gonna replace the head with the newer one sooner or later.

I gotta also figure out how to get the engine to idle between the two points where it seems to gravitate to - either 600rpm or 1,400rpm. I thought the timing was right and the carbs were synched, but I guess I'll have to try all that again. I have a feeling something's blowing/not firing right as well, but again, that's easy enough to check out.

Getting there - again . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 18, 2011, 04:55:59 PM: Hmmm. I spoke a little too soon.

There's good news - jetwashed the engine and it turns out the stuff on the upper fins was just residual oil from the headwork that had dried and then solidified when it heated up. There's no leaks from the top end.

However, the not-so-good news is that the joint where the barrels meet the crankcase at the front of the engine (i.e. around the base gasket) leaks. Quite a lot. I'm sure I had this happen before when a shop put the engine back together. That time one of the rubber rings that goes round the base of the individual cylinders had been poked up too high into its recess, causing the leak and the oil pressure warning light came on. This could be the same deal (without the oil pressure light) - or it's the areas where the surplus oil drains back into the crankcase from up in the head. Either way, it's all got to come apart again (take head and barrels off). Arse it. Oh well, I'm getting used to it now.

There's also white exhaust coming out of 3 and 4. They're the same end where the camshaft lunched itself, but I have a feeling they're exhaust leaks (the joints from the headers to the head aren't exactly wonderful). It also wouldn't surprise me if the valve seals had hardened with overheating and now leak a bit. Guess I'll have a look see while I'm in there - again.
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on June 18, 2011, 06:38:58 PM: Neil, the cost for gaskets and o rings alone must be mounting up, still as you say you are now getting used to taking apart and reassembling the engine so time wise it should be a doddle
When i build engines i use blue hylomar or copper grease on the gasket surfaces depending on where it is just to aid sealing, it seemed to work a treat on my F2
Anyway chin up mate your get there in the end, i am hoping your next post on the subject will be full of joy, you deserve a bit of luck
Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 18, 2011, 08:40:46 PM: Pete - thanks so much for the kind words. I thought about using copper grease on the base gasket but decided against it for no very good reason. Should've gone with my first instincts, but again, I've got another spare if the one that's on there turns out to be dead.

Your post couldn't've come at a better time, because guess what? Bikewise, today got a lot worse.

After putting the 750 to one side, I decided to go get some food and thought I'd take the SL350. What could go wrong? Well, the top of the left shock absorber separating itself from the bottom four miles out wasn't something that would've immediately sprung to mind. But that's exactly what it did. Oddly, I didn't notice anything wrong until I got off the bike (although the spring had wedged itself against the frame, so I didn't lose much in the way of rebound) but I needed recovering 'cos there was no way I was riding it like that once I'd noticed it. So I don't think I was ever in any real danger.

However, what the separation did do was take a chunk out of the rare-as-hell-and-virtually-irreplaceable sidepanel which I spent a bundle on getting painted. Fortunately, it's not holed or cracked - I think it's just taken a layer out about the size of a 10p coin - but colour matching is going to be a pig of a job. On the upside, Silvers have got the collars that disappeared themselves when the shock disassembled itself are still, so at least that's not lost. Guess that's one of the benefits of such a rare bike - no-one else needs the parts.

It's not good, but I can only look at the whole sorry mess and say hey, it could've been so much worse. I'm still in one piece, and the remedial work on both bikes is more time than money (well, maybe not the sidepanel . . . ).

Right, let's tear down that 750.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 18, 2011, 11:21:50 PM: 2 hours - that's how long it's taken me to get the engine down to the crankcases and tidy the garage. Not bad, huh?

Looking at the areas where the leak was emanating from, it seems to be attributable to one of a couple of things - the favourites are a poor seal around the thin strip of gasket covering the case near the front of the cam chain guide, or something due south of the up oilways (round the rear cylinder studs) from the crankcase. The surfaces are completely flat, so it's not warp or scarring, but I can't remember if I used new o-rings around the oilway studs. Having said that, if they weren't sealing, I would have thought any leakage would have taken the much shorter route to air - i.e. go out from the cylinders backwards and onto the top of the crankcases. There was also nothing particularly unusual about the o-rings around the cylinder bases. Whatever, it shouldn't be a particularly tricky fix.

I'll let the faces a while to dry out, and run them over with thinners before putting everything back. I'll also pull the valves, check the guides, clean up the seats, gently re-lap the faces and put on new seals. I already kinda live by Brian's earlier maxim of never throwing anything away, and numerous engine gasket kits have provided me with more than enough spares. 'll also clean the cylinder bases and reseat the larger o-rings before reassembly.

Suffice it to say I've got the bit between my teeth. The problems I've got are ones that I understand and can fix, so it's just a matter of getting on and doing it. I find it's easier to be motivated by this kind of situation than be down about it, 'cos I'm pretty sure it just needs a bit more twiddling to get it perfect. And by perfect I mean oil tight and running without smoke. Talking of which, pistons 1 and 2 had some carbon deposits on the tops, but 3 and 4 (remember 4 was smoking a bit) were pretty much clean as a whistle. Dunno what - if anything - that means.

Tired now. Busy day.
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on June 19, 2011, 08:59:18 AM: Well done Neil, positive attitude gets you everywhere, these old bike can be a test of anyones patience, i have lots of oldish jap bikes each one has presented me with some sort of problem , but evrything comes good eventually,
I am now off to ride some of mine today i think first of all i will take the 750F2 up the oakdene cafe, then come back and take the K1 out for a 30 mile or so ride just to keep it healthy, then when back from that ride i will go ballistic on my FZ1, for an hour to pump up the adrenaline, it keeps you feeling young you know
pete
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on June 20, 2011, 12:30:59 AM: Looks like the weather held for you today . . .

On further inspection, it looks to me like the leak around the cylinder base was caused by a casting flaw in the underside of the cylinder block. There's a small patch around one of the oil returns that isn't completely flat - it's very slightly rough. It doesn't run the width of the band from the return through to the engine exterior, but the pressure inside the crankcases now that the oil pump has been overhauled and works at pretty much maximum potential is enough to force tiny amounts of oil/air out.

So I've refitted the base gasket after coating most of it in copper grease and the bit that sits over the rough patch (and areas in front of the oil returns) with thin coats of sealant on both faces. Top went back on with pretty much the same ease as the last time I put it together, and there's just a few jobs left for the re-rebuild to be completed. One benefit of picking up he new head I hadn't foreseen is that it came with better fitting exhaust flanges - the bits that join the exhausts to the head - than I've got on mine. I never really thought about it until now, but mine were really sloppy, which could explain the with smoke from #4 (I always thought it was an air leak).

So that's cool.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 03, 2011, 10:40:24 PM: Well, I thought it was cool. I was wrong.

After stripping and rebuilding the top end, I got to run the bike last week. Top end was pretty much fine, and the smoke from #4 was residual oil (WD40 or similar) in the exhaust pipe. However, I couldn't help notice what seemed to be oil dripping from the front filter housing. Closer inspection revealed the housing was fine, so the next logical conclusion was that it was old oil that had leaked from the cylinder base, dried on and then liquefied when everything heated up. Sadly, that would just be too easy.

Seems the base gasket leak masked a smaller, but equally significant leak - from the joint between the crankcase halves. Never seen that before, but it's there. Like the other leak, I'm putting it down to a properly functioning oil pump increasing the internal pressure, but that's little consolation.

Looks like the only remedy is to pull the engine, flip it, unseal and reseal and put it back in again. At least that way I can be sure it's done right.

I'm sure every step I go forward is getting me closer to having a properly sorted bike, but it sure as hell is putting me through the ringer to get there.

:'(
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on August 03, 2011, 10:47:22 PM: Do I remember there being an "O" ring in that area?
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 03, 2011, 11:15:25 PM: Oh yeah - the big one that goes round the oil path dowel. Both are there - and were new when I put the two halves together last time.

I'm struggling to remember now, but I have a feeling that when I put the bottom half on, I had some trouble with one of the bearing retainers not fitting quite right. I replaced all of the bearings with SKF's and had to have retaining grooves cut into the sides of a couple of them - and one in particular was a very tight fit. Anyways, I thought I'd got the cases squared away but hadn't, and had to reopen them - and I guess I disturbed the liquid gasket stuff.

Whatever - it's going to be hard work. Again.

>-sigh-<
Title: Re: Rewiring K2 with later high beam switch
Post by: mick on August 04, 2011, 08:54:23 AM: Keep plugging away Neil it will be worth it in the end ;), cheers Mick.
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on August 04, 2011, 01:11:16 PM: That engine is giving you so much hassle, i hope you get it oil tight and running fine, maybee if its up and running you can join us at box hill on August 28th, where hopefully a few sohc members will meet up
Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 06, 2011, 11:28:25 PM: Well, it's been a day of ups and downs.

We pulled the engine earlier today, flipped it and opened it up. It was fairly obvious where the sealant was missing - there was a space about an inch wide, which is very weird, but hey. We cleaned the mating faces before applying new sealant and with all that done and the halves bolted back together, we flipped the engine right way up. Everything checked out (gears and crank-wise) and we're just moving it back to the bike when . . .

. . . we noticed what looked like a small silver plug that had fallen out of the cases. On closer inspection (and some hunting with a torch) it appears to be the internal end covering of one of the cylinder studs - I can see the top of one if I look very carefully. The piece of casting is only about the size of a 20p piece and it's a couple of mm thick; there's no thread on it, but it's got a domed indent in the centre. We didn't touch the studs this time - no need. All we were doing was taking the bottom case off and putting it back on - so I can only assume the end cap had fractured when I replaced the standard studs with heavy duty ones and it been waiting for the right time to fall off . . . and that time happened to be now.

I can't see any other case damage anywhere, and it's certainly not spread or cracked anything else, but what I'm hoping someone can tell me is whether it's safe to run as it is - insofar as will the rough casting hold up to being continually splashed with engine oil? I know the cases are strong enough as they are, but I'm just a little concerned that the unfinished surface left by the missing cap might be too porous and/or should be resealed to stop it crumbling.

I'm praying that it'll be fine as it is, and that I'm just me being over cautious - I really don't want to go through an entire stripdown again.

>sigh<->again>
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 07, 2011, 10:50:16 AM: I'll answer my own question for those who're interested with the wisdom of Hondaman:

"Boy, I know all about the hectic part!

The casting: the main reason these were closed on the bottom was to keep oil seepage up those threads to a minimum. Honda has always been concerned that their engines should be dry on the outside. If the engine is still open, you might try using a bit of JB Weld epoxy, fresh and well-mixed, after cleaning the site with acetone or lacquer thinner. This epoxy work well by gripping those pores and sealing into them, and it withstands engine heat easily. It is impervious to hot oil, once cured. It is a mainstay of the repairs I have done to both these aluminum engines and cast-iron ones, for years. But, it must be FRESH, not old, and well-mixed, and applied no more than 3mm (1.8") thick.

It's actually good that the little piece fell out now: it could have popped up into the tranny gears and locked them tight while snapping into a hard shift into 2nd gear near redline. Makes a real mess (and we won't discuss how I know about this little event...). :-D"

Bearing in mind my 350 and 450 both have open ended cylinder stud holes, I reckon it'll be fine as is. Which is something of a relief - as is the fact that it went when it did and didn't wait to spring a really nasty surprise on me . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on August 18, 2011, 08:29:43 AM: Lets hope thats the last of it neil, you deserve a bit of good luck with this engine,

Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 21, 2011, 05:24:13 PM: Yeah - that's what I thought. Sadly, the engine has other ideas.

There's a leak between the crankcases in the sprocket area - the part of the cases that sit between the sprocket and gearbox. Yes, it's definitely there and not the seal behind the sprocket; I cleaned everything with thinners and then put talc on it to see if I could trace the problem (which was oil doing more than just dripping off the bottom of the engine).

Christ. Either I'm cursed or this f*cking engine is. Still, it's not a mechanical problem, so it's not an expensive fix; just time consuming. Again.

<sigh - again - sigh>
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on August 22, 2011, 07:20:50 AM: That might be the locating ring holding the cases slightly apart mate, something physical has to be stopping them going together with all them bolts on it
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 23, 2011, 09:16:43 PM: Guess that's possible - I know one of them was a pain in the arse to fit.

Having said that, the leak isn't near to or parallel with one of those locators (as far as I can recall). Also, the hole is sooooo small - and it's only leaking from that point - that I reckon it's the sealant that's the problem. Added to which, I'd've thought I'd have bigger problems than a pinhole oil leak to worry about if one of the locators was out of whack. ;)

I'll let you know . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: K2-K6 on August 23, 2011, 11:18:19 PM: I've never used anything but Blue Hylomar on these motors for all flat gasket surfaces and it always works.

Clean the surfaces with petroleum based cleaner, apply thin film of BH to entire surface, no excess though and let it dry for 15mins or so before assembly. If there are variance in flatness then coat both surfaces.

Don't know if you're using silicone? but I rarely use it on any engine as I just see it doesn't match the application unless specifically requested or the surfaces have such a poor alignment to need big gaps filling in.

Those Honda castings are usually quite good and I've not worked on one that I consider would need that amount of sealant.

This may be related to your oil flow problem, but I've often found silicone gasket material inside motors when stripping them as most of it squeezes out of the mating surfaces. It's not good, and once dismantled a Kawasaki Z900 that had an oil pick-up that looked like a pizza there was so much silicone on it.

With any cams I've always used a very fine graphited grease on all bearings and lobes to prevent pickup on any initial turnover, you don't need much but just enough to coat lightly each surface.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on August 24, 2011, 12:02:11 AM: I'll be using ThreeBond on the case halves. I generally use acetone to wipe down the mating surfaces and as far as I can tell, they're properly flat and not flawed. Which is a little more than I can say for some of the various sidecovers. I've been beset with minor leaks from those, too, and so this time I've taped some fine-ish wet 'n' dry (600-1000 grit) to a flat board and given the mating surfaces a rub over. That process revealed a number of high spots, which are no more - hopefully that'll put paid to the minor seeps.

But believe me when I say I'm having a run of extraordinarily bad luck with bikes right now, which includes:

- two water leaks from somewhere in the front outer case surfaces of my ST1100 (main transport). Looks like they are around the timing belt cover - the water pump housing sits behind the timing belt, so one of them may well be a rubber seal in that assembly; the other seems to be from somewhere around the front clutch cover, which makes much less sense. Whatever, it's a job that I have no desire to tackle myself right now (with the 750 already in bits) and is likely to be so expensive, it might be more than the bike's worth

- whilst admiring my newly powdercoated SL350 frame that I collected today, I've noticed a dirty great crack in the RHS swingarm spindle mount. I thought I'd got all of the anomolies on that frame sorted before I got it coated, but I guess not. Yes, it's structural so no, I can't simply patch it. I gotta get the powdercoat off and get it welded, then re-powdered.

If I didn't have bad luck, I guess I'd have no luck at all. Suffice it to say this really ain't my year.
Title: Not again . . .
Post by: the-chauffeur on October 29, 2011, 09:49:52 PM: I'm back . . .

I can't quite believe this. The 750 cases are leaking - again - from the same place as last time; the joint that runs across the part of the casing that separates the gearbox from the drive sprocket. Everywhere else on the crankcase joint is solid - no leaks from the front or other sides. As before, it's a tiny, tiny hole, but just enough so that as the crankcase pressure builds it lets out a small stream of oil. I really, seriously cannot understand why the leak has appeared - I checked and double-checked this area to make sure it was flat because of the last leak, and trowelled on the sealant in that area. Frankly, I had some concerns that I might have overdone it sealant-wise there, but nope - seems not.

Two observations: the lower casing has (very briefly) come into contact with a drive chain at some point in the long-distant past and there are a couple of shallow channels that are the chain width apart that run about 1cm across the join. And although I'm pretty damn sure the cases are the original matched pair, the lower case edge protrudes few fractions of a mm past the edge of the top. The leak is coming from somewhere between the channels, but the hole is soooo small, I'd need a microscope to see it (it's one of those where the oil doesn't stream out - it just kind of accumulates along the tiny lip and then runs off.

I've drained the oil and cleaned the sides up with white spirit and a cotton bud dipped in acetone. I've also run a couple of sharp tools along the area of the join to tidy it up. Bearing in mind the lengths I've gone to so far, and the lack of success I've had with this particular area, what I plan to do - and I need some guidance here - is to completely clean the area around the leak, (carefully) dry it out with a heat gun and then run a thin bead of JB Weld (metal epoxy) along the join. The US board is full of stories of folks who've used it to fill in/rebuild broken cases, so it seems the least destructive/best plan of action right now. Gasket sealant clearly isn't doing it, so I figure that before I pull the engine again I've got to try everything I can to try to cure that bloody leak - and carefully applying with something more substantial may be the answer.

On the subject of leaks, I think I've identified why my side cases have been leaking. After flatting them off and refitting them, I've found that no matter what type of gasket I've used (getting progressively thicker) they're still seeping - more from the front left than the rear left. But it dawned on me today that the leaks are from around the fasteners that fit inside locating dowels. What I guess is happening is that the side cases are being held very slightly proud of the engine faces by the dowels, and so even though I've spaced the sides sufficiently with thicker gaskets, they're not taking up the space the dowels create. So I s'pose I gotta shave the dowels down very slightly . . .

Thoughts on the joint issue very gratefully received . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: K2-K6 on October 29, 2011, 10:23:04 PM: I've no experience of JB weld so can't offer anything contructive or otherwise on that score, just some other general comments.

Fixing a leak from outside is usually marginal in almost any situation you can think of especially if pressure is high. This should be a low pressure location so odds are a bit better and with really good cleaning you may stop what appears to be almost a capiliary action, so on balance worth a considered effort.

Things like isopon filler stick really well to clean alloy and if not suitable can be very carefully filed away so very low risk.

Are you confident of any breather cleaning to help avoid crankcase pressure?

The dowels do have to be checked if you've reduced surafce level at all, bolt on without gasket and check with feeler gauge to get accurate read on it.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on October 29, 2011, 11:20:28 PM: Thanks K2.

Capillary leak sounds about right, and I know exactly what you're saying about external seals. I've been wondering about maybe v-e-r-y carefully filing/Dremel-ing a V shape into the join faces to create greater surface area for the epoxy to stick to, but decided to go with the flat for now on the basis that doing it this way is less invasive/more easily reversible.

Not quite sure what you mean about the breather but the pipe is new and doesn't have any snags or bends in it. I have, however, got a question about where the breather should join - something I've never properly understood. On my K2, the oil tank has 2 connections on the rear - one high up for a larger pipe, one lower for a narrower pipe. Right now, I've got the breather pipe from the cam cover going to the top connection on the oil tank; I've also got a small pipe running from the small lower connection to a similar size connector on the rear of the crankcases. But I don't know if that's right. Should it be closed circuit or should there be a breather-to-air? And if there is a breather-to-air, what are the connectors on the rear of the oil tank for?

And thanks for the pointer on the dowels - feelers are the way to go.

Cheers

I'm sure I've asked for advice on this before

There are
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on October 30, 2011, 06:10:02 AM: Hi Niel, you have the patience of a saint, i would have smashed the f ing bike up with a hammer by now
Anyway, in part answer to your questions, i would say you have a good chance of success using an epoxy filler of some sort to stop your leak, i have used a 2 pack wood filler to repair a gaping hole in the side cover of a klr engine with great results, what happened is i fell off my KLR600 while trying to off road it and went tumbling down a bank, besides my injuries my bike had taken a beating, worst off all the gear change had gone through the engine casing making a 2'' crack just behind the magneto, as a very temporary bodge i cleaned the casing with thinners and run a small grove up the crack to open it out a bit roughed up the surrounding area cleaned again then filled with the epoxy wood filler which is almost identical to car body filler and reasonably flexible, that was 3 years ago and i use the bike every week it has held up really well and i have not been bothered to do anything more to it, so i recon it is worth you having a go, the JB weld is really good but a good 24 hours to cure, 2 pack epoxy is 20 miutes to cure and much easier to work with so there you have it nothing to loose really
Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on October 30, 2011, 01:39:41 PM: Hey Pete

I'm sure the expression tortures of the damned was invented just for me. It's unbelievably trying, but it feels soooo close.

I've gone with JB Weld because I'm not in any hurry, and I need whatever covers that area to set - solid. I decided to use the Dremel-thing which has got a kind of extension cable on it to get in and very, very carefully open the edges of the seal. After mixing the JB, I smeared it across the join, initially with a little paintbrush to try and get as good penetration as possible and then went over it with a finger. After getting as much into the gap as I could, I smoothed over the top (carefully) with a little white spirit. If it dries the right colour, it's going to be quite hard to see - except for the fact that there's no visible join.

While sorting that out, I feeler guage-d the side covers and found that two out of the three dowels were holding the side covers off by about 0.15mm, the kind of gaps that would need some fairly heavy duty gaskets to take up the slack. I've shaved down the dowels and checked everything was flat before refitting the side covers. Let's hope that's at least one step in the right direction.

Meantime, any thoughts on the breather hose locations? Something I forgot to mention earlier is that if I've run the bike and then open the oil tank while the oil's hot, it will hiss as the pressure escapes (not unlike removing a radiator cap from a hot engine, but nothing like as spectacular . . . ). I dunno, but that kinda doesn't seem right to me. And knowing that SOHC twins of the same age vent to air, I'm a bit concerned I might have introduced a closed system where there shouldn't be one . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on October 30, 2011, 01:44:25 PM: That dont sound right pressure in the oil tank, it could explain the bike having any excuse to leak oil, i will have a look at the f2 and k1 to see how it is set up
Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: UK Pete on October 30, 2011, 10:04:55 PM: Neil the bottom pipe goes to the crank case the top is to air, the rocker cover should end up in the air filter, on the f2 via a condensate trap
Pete
Title: Re: Rewiring K2 with later high beam switch
Post by: K2-K6 on October 31, 2011, 05:06:32 PM: Niel, I haven't got my K2 where I live currently so can't check the exact layout for you.

I'll look at what info I've got to see if anything useful is there.

The oil tank on the bikes I've got have never had any pressure build-up in them even if you open them when running so something odd there. It's fairly conventional to vent from the top of many engines into the air filter to burn off any oil smoke that may be present.
Title: Re: Rewiring K2 with later high beam switch
Post by: K2-K6 on October 31, 2011, 07:51:01 PM: Just unbolted a UK K6 oil tank to look at the back/conections, bottom pipe is definitely conected to back of gearbox casing and reaches up to the top inside so if overfull it would "leak" into the engine.

Cam box breather just goes to air down the back of the engine, it could be US spec that had vents into the airbox to reduce emmisions as any oil mist would be burnt by the engine via intake which ties in with them pushing manufacturers first into that scenario.

It does seem like you've got yours to over pressurise itself and should at some point be vented to atmosphere to avoid a build up of crankcase pressure.

It would make sense for both top of oil tank and top of cam cover to vent into the airbox to contain emmissionsas this would probably create a small negative pressure in the engine.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on October 31, 2011, 10:10:00 PM: Thanks gents.

Looking at the various fiches, the K2's are showing as having separate breather pipes from both the cam cover and the upper rear of the oil tank. Of course, both are long obsolete, but the fact there are 2 listed, and the airbox doesn't have the breather entry point the later models come with suggests to me that both vent to air - and the advice I got previously was wrong. I reckon K2's right about emissions, and that over the life of the model range, at least one of the breathers was connected to the airbox.

With that in mind, I've swapped the cam cover breather hose for a longer piece and put a small quantity of sponge in the trailing end; just enough to (hopefully) catch drips and stop anything nasty going up the wrong way. I've also done the same to the shorter piece, the top end of which I've left connected to the top oil tank connector.

I guess that with the new routing arrangement the crankcase pressure should be significantly reduced - and that I won't need to pray too hard that the JB Weld will put paid to the leak.

Here's hoping . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: K2-K6 on October 31, 2011, 10:20:43 PM: It'll be interesting to see how you get on and if it's leak free.

I was slightly puzzled that you had so many leaks compared to my experience hence the breather question.

Hopefully you've finally got all the bits sorted as they are nice to own.

Nigel.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on November 02, 2011, 05:36:20 PM: I'm still holding my breath and crossing my fingers . . .

. . . but I think I may have finally put paid to the oil leaks. Took the bike out for a 6-7 mile run today; not a major expedition, but enough to get the engine hot. No leaks and no squaks. Nuffink. I keep going out to the garage to see if it's dropped anything - force of habit - but so far, we're all good. After the best part of three year's work (on and off) I think I can maybe start relaxing about the engine.

I reckon that along with the filler, the massively reduced crankcase pressure levels won't trouble the top-to-bottom case seals any more. Which is a good thing. I'm still amazed at how close the JB Weld colour is to that of the cases. It's really, really close. As for the side covers, not even a hint of oil from them. And the 2.5mm o-ring plus a healthy smear of sealant has put paid to neutral switch leaks, too.

So thanks for all your help folks, although this isn't quite the last of it. It's time to start tidying the bits that don't look so, well, tidy and getting some (hopefully) worry-free enjoyment out of the bike . . .
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on November 02, 2011, 06:02:56 PM: Well done, my personal opinion is that 90% of you leaks was the crankcase pressure mate, ride it and enjoy it now----sez he now it's 'kin freezing and going white!!
Title: Re: Rewiring K2 with later high beam switch
Post by: K2-K6 on November 02, 2011, 09:02:50 PM: That sounds like good news, and some positive progress.

Plenty of time now to work on other stuff before next spring.

I've always painted the sprocket area with a very pale gold hammerite as noboby really gets to see it and it looked nice to me and easy to keep clean/inspect.

That point you said about the chain making marks in the cases, I feel that this happens when people let the chain get to worn (pitch elongated compared to sprocket) and make an adjustment to the slack and think it's ok. The engine braking is fairly strong on these with the thottle completely closed and any error pushes the chain off the front of the front sprocket. It's this that causes the marks and sometimes if severe will bunch and smash the cases.

With a new chain it will never reach the cases even with too much slack in adjustment of the main runs if that makes sense.
Title: Re: Rewiring K2 with later high beam switch
Post by: the-chauffeur on November 03, 2011, 08:41:16 PM: Again, Ithankyou, Ithankyou . . .

Bryan - gotta agree that the pressure got to the engine and caused/worsened the issues with the case join at the rear and the neutral switch. Actually, I'm sorta surprised it held together as well as it did and that I didn't get leaks from other joints. As for the side cover leaks, there's no doubt the pressure didn't help, but then I shouldn't imagine cavernous gaps between the covers and the engine faces were doing me any favours at all, either. And it's still dry today - hooray.

K2 - good point about the chain. I've got no idea when the marks were put on mine, other than at some point before I got anywhere near it. Must've happened a while ago, 'cos when I got the bike it had a 16t front sprocket on it, and it'd have to really go some to connect from there. I've got an 18t on now, and that feels great.

Ages ago I tracked down one of these:

(http://farm7.static.flickr.com/6045/6309524336_af7bedbd00_b.jpg)

It's a NOS case protector. Think I paid about
Title: Re: Rewiring K2 with later high beam switch
Post by: Bryanj on November 04, 2011, 05:22:53 AM: Should fit with a 17 tooth which from memory was the standard for years