CB550 First Build - Hondvarna?

[cinqmars2]

Those carbs are the same as fitted to all 500/550 EXCEPT the K3, and whilst they runn richer are far easier to stip/clean/get parts for

Ace! Thanks Bryan, appreciate the help!

[matthewmosse]

In theory I daersay that is correct but in practice I've never found any crud having found it's way down the inlet or exhausts either having installed such engines or stripped them as a precaution, I've never had engine failiure that I'd thought might be attributable to anything entering by this route - I always open problem engines up to take a look and haven't found scored bores or bad piston wear, appart from one engine that had all 4 pistons missing their top rin and all 4 pistons and head scarred badly, since several broken rings were found in the sump and gaskett goo was everywhere I think extreme bodgery were the culprits on that count - the engine went on to do several years commuting given some cheap pistons from another engine and eventually dropping 2 valves - but given it's history I wasn't surprised, it looked like it had been run with all 4 top rings in bits in the engine (worst assembly job ever?)- the piston tops were well pitted - I've no idea what could have caused such a failiure. I prefer to test run an engine and get a really good idea as to internal condition by looking at how it preforms then fix accordingly if needed.
My personal approach would be to stick a hoover over each port to suck any crud out and turn the engine over by hand a few times then try runing as is. Meaning no disrespect but having messed up bits myself and seen as many by others in my earlyer years I'm very aware that inexpirienced engine strip and rebuilds can cost a lot of money and effort and destoy good components. Conversly the 500 and 550 engines are tough cookies and can go for many many miles with basic servicing - 180 000 on my 500/4 sidecar outfit with no engine work up to that milage. Only work it will need for the original motor is new gaskett set fitting and new rings in all probability, the gearbox was the issue, jumping out of 2nd and 1st. I may get a more expirienced mehanic to check valves and crank bearings whilst it is appart but going by visual inspection they are probably ok. Of the 10 or so engines I have either in bits or as runners from bikes I've got as projects, the engines that are factory builds rather than owner rebuilds are the ones that run best- that is if my crude diagnosis method is correct, all unspoilt looking phillips head screws and bolts being right and undoing with that cirtain satisfying noise and feel = factory build, owner rebuilds more typycally feature Allen head bolts that so often foul rocker covers etc - the list goes on - either way I prefer the old addage of if it ain't broke - don't fix it. I've had US inport engines that at first leaked like sieves, smoked like the proverbial and sounded nasty that have come good after 500 miles use.

[cinqmars2]

Thanks for getting back to me guys!

Hmm ok, well Engine 01 has a few parts missing, like Oddjob noticed, the tach, the points are also missing, there are numerous replacement bolts around the engine, ranging from hex to philips in varying states. This engine has definitely been tampered with so it's safe to say that it's not still the factory assembly. As neither I, nor the previous owner, have had this running, I can't say what condition it is in to perform any running diagnostics. I think the best approach would be to strip it right down, gives me a chance to clean it and get it painted if it's in good running order, and if there are any major issues, hopefully they will become apparent while it is in pieces...

Anyone got any techniques for noting and organising components during a total strip down? 

Oh, and Matthew, where you mentioned your engine having the 'worst assembly job ever' I'd be a little more reserved and say that at may be the worst assembly job...so far

[Rozabikes Tim]

Also some photos of my carbs for help with identification 

This is after a good lemon juice + vinegar cooking, all need a full rebuild.

Hi

carb finish looks good. What is involved more specifically with lemon juice + vinegar cleaning method you refer to? Were the carbs pretty clean and not oxidised to start with.

thanks,


Tim

[cinqmars2]

Hi Tim, I had before + after pictures on my phone, but it was stolen a few weeks ago! Gutted.

They were not oxidised as such, they were just very dirty, a lot of set-in fuel and muck from years of avoiding any cleaning at all, the bodies were unevenly stained and discoloured. I found this photo on Google, this is pretty close to how mine looked. After a spray with some carb cleaner and a quick scrub to get rid of the looser stuff, I boiled them.

The method I used was to boil the carbs one by one in a large pan for about two hours each. Maybe five litres of water to one cup of lemon juice and a couple of capfuls of white vinegar to be certain. Although saying this, you can find all kinds of ratios online that people swear by, ranging from 10:1 to 1:1, I don't think citric acid will really inflict any real damage to carbs. They were completely dismantled to get into as many little places as possible, if I had the means I would have liked to have used an air compressor to blast out the remaining water, but had to let them dry on top of my wood burner instead, wanted to get any moisture out as soon as possible.

[cinqmars2]

Oddjob, thank you so much, there are surely enough tips and tricks in there to keep me in check!

[Rozabikes Tim]

Thanks.

Have been doing my 400/4 carbs with ultrasonic cleaner / standard solution.  Very good but could be better - may try your concoctiion in the ultrasonic cleaner.

Ta for the info.

[cinqmars2]

Quick update, I dismantled the only straight pair of forks last night, the oil was well and truly spent, but all parts look to be in great condition inside. The lowers are chipped up, some are too deep to even bother sanding down so I think a good paint job would be the best approach for them. I cleaned out all the oil I could by rinsing everything in the shower, this expelled a lot of debris with rapidly flew down the plug so i never got the chance to actually see what it was. I don't know if was metal, plastic or just gunked up oil? There is no notable wear and all parts were present and correct according to my manual so I don't think it's cause for too much concern. The tubes were the main thing I was after from the forks as they are totally straight, but they do have a lot of pitting, some showing corrosion inside the travel margin so these will need a grind + re-chroming at some point. Expensive, but I think it will be worthwhile for a smart. new-looking pair of forks. I reassembled them with my original, polished lowers to keep everything together.

[cinqmars2]

So a little bit of progress, we've had a new arrival at the studio! A lovely 18v impact driver, which means I've been able to get inside the engines. I promptly shattered two bits with it fighting with those ridiculous philips bolts, what a strange decision for Honda to make, bolts which undergo pretty extreme tightening, accesible only with screwdrivers? Makes no sense to me. I'll definitely be replacing these with stainless allen bolts. After some slicing of the screw heads I managed to get the most stubborn ones out. Dismantled the alternator, points, clutch and oil pump before I split the case. I've only been working on Engine 02 (the trashiest looking one) so far. Actually looks pretty straight once inside. What am I looking out for mainly here? Wear in the journals? How do I know if they're too worn? There was some crud in the oil pan, but nothing compared to some of the projects I've seen online, filter was dead clean surprisingly.

Clutch apart:


Lower:


Upper:

[Bryanj]

Only safe way to judge bearing wear is plastigauge, but from what i can see of the shells they look OK.

If you can put up some closer pictures we can give you a better idea---DO NOT remove from cases unless you can bag them so they go back in the same place as there is no marking on an old shell to tell you the size

[cinqmars2]

I've left everything in the cases, all journals, all gears and gear selection forks, I have a couple of photos from the top case but good light is not on hand in the studio and had to take photos it has to be a wide open aperture with a slow shutter. No depth of field and blurry when hand held. Not ideal by any means. I'll get a good selection of the journals up close this weekend.



On another note, I brought one of my rebuilt carbs into work today (it's slow at the moment and I've got a fair bit of free time) to compare it to other people's rebuilt carbs online. My Internet at home is shocking so it's best done here. I feel that my Keyster rebuild kit may not have been the best purchase, the float cut off valve seems to need a fair bit of pressure to actually engage the cut off, the weight of the floats aren't enough by themselves. Will the buoyancy of the floats in petrol have more pressure?

They're just sitting on the valve wide open



The old valves are intact and I assuming will work better than this. Anyone else had a similar experience?

[K2-K6]

As long as the float can push the valve up within the entry port, then they usually seal ok and are not dependant on compressing the spring as the float is too light to do that on it's own.

This may help with the crosshead screws.....before you try to undo each one, use a steel bar (flat end approx 12mm dia) and gently peen the screw head by tapping with a hammer on the bar end...this has the effect of reforming some mild damage if present around the cross grooves and can help to break corrosion affects prior to undoing the screw....you may have to also tap the screwdriver bit into place to get a full engagement if the screw was more badly chewed.

[cinqmars2]

So it's been a long time since my last update, not that I haven't been doing anything, but not as much as I'd like...

Firstly, I was reassembling my carbs, then realised I had lost one of the leaf springs that hold the main jet in place. Gutted. After searching for a week straight online I couldn't find one anywhere. You can imagine how pissed off I was at myself, but what do you expect if you have your carbs in bits for three months? I found a complete set on eBay and deemed it worthwhile to buy them, they looked rough and the seller (a motorcycle breakers yard) was reluctant to look through the internals for me. Regardless, I took the plunge and for the price of £75 I had a new rack of carbs heading my way. When I got them, they looked a lot healthier than they did in the photos and actually looked better than my original ones did before I cleaned them. After opening them up I was greeted by the site of (extremely recently) rebuilt carbs with mint float bowls on every carb. Things are looking my way 

The other area of progress was the stripping of my tank, all the paint is off and the thing is dead tight, had a few litres of vinegar sitting in it for a week and the inside came out sparkling. That is, until I emptied the vinegar out and the flash rust kicked in in about 15 seconds flat. Square one on the tank. Ace.

I also bought a rear hoop from eBay, I was a little dubious, but the thing turned out to be great, no adjustment needed and it's round all the way along the bend, £25 well spent in my mind. After knocking together a mock up with the tank and some polystyrene I found for the seat, I took the plunge and welded the thing in, this is the first time I've ever welded for an application, before this was just scrap steel to get to grips with it. Very happy with the results! Dead straight, and dead strong!

[cinqmars2]

Also, a slow day in the office has meant I got the chance to piss about in Photo'chop.

This is the direction I'm headed, colour scheme reminiscent of the old Husky crossers, that's just about where any similarities will end though.