Honda-SOHC

Pete

There are no oiling holes in the cam towers that feed directly onto the shafts.  The feeds are the oilways you've seen spraying, and one each under the ends and centres cam journals.  The shafts rely on the holes on the top of the towers to collect spray - which isn't exactly an ideal method given the thrashing the oil pumps sometimes get.

It's probably a bit late now, but have you seen HondaMan's post on the shaft differences, top end oiling and modifying the towers?


 

Or more specifically, a silver variant of this kit on a bike engine?

I'm torn between using the stuff above and not putting any paint on the 750 engine when I put it back together (and just coating it in ACF50 every now and again - works well on the 350 and 450).  I basically stopped using paints when I couldn't find anything that was fuel resistant - every time I've used paints in the past and had any sort of fuel leak (no matter how minor), the paint has just lifted straight off leaving the engine looking awful. But watching the videos and looking at just how comprehensive these kits are, I'm wondering if this stuff will be more fuel resistant than anything else I've tried so far . . .

Thanks.

I've just had Brian cut a couple of grooves in some bearings for me.  IIRC, the bearings I wanted were no longer available from Honda, so I didn't really have much choice.

Must confess, I don't know much about the procedure beyond what he told me, but I gather that to do the job properly you need a fairly specialised cutting tool.  Fortunately for me, he's got one lying around in his workshop, so I got some SKF bearings I had with the blank sides machined to match those that came out of the bottom end of the 750.

Don't s'pose that helps much, but I'm sure Brian could give you some pointers if you don't have any luck anywhere else . . .

Just thought I'd add that I went into see Brian today to pick up the headwork he's done on my 750.  Nice.  New valve guides fitted and reamed, seats and valves ground/reground, all threads chased/repaired and so on.  He's also grooved some bearing housings, TIG'd up my frame (got a Gordon kit fitted) and repaired a couple of switchgear housings.

He was in the process of skimming a cylinder block and head - so I guess he can do those, too. 

With prices of bits moving ever upwards, I thought I'd repost this here under a title that can be found (it's taken from a much earlier thread with a heading that doesn't reflect the content).  If you're going for an authentic  750 resto, you'll need to get hold of the various warning stickers that go on the frame.  

There are plenty of folks on eBay trying to flog them for silly money, but the following stickers are almost certainly available from Honda direct (and at a fraction of eBay prices):

1; Made in Japan - 87125-041-680 - headstock



2; Engine oil - 87125-300-010 - oil tank cover



3; Exhaust Caution - 87504-028-670 - swing arm/chain guard



4; Helmet holder - 87511-323-670 - under seat



5; Preserve Nature (black text) - 87560-323-670ZA - tank above filler cap



6; Preserve Nature (white text) - 87560-323-670A - tank above filler cap



7; Preserve Nature (European later type) - 87560-375-680ZE - tank above filler cap




8; Tyre Caution - 87505-341-670 - rear fender

(see picture below)

Unobtainable direct from Honda

(Note: although only one number is listed, the original sticker was in two pieces. Two types of repros are available - one is a large single sticker; the other is as the original two-piece)


9; Battery Caution - 87506-425-770 - plastic rear fender under seat

(see picture below)

Unobtainable direct from Honda


CMSNL do their own kit - =http://www.cmsnl.com/products/0617d-300-030-cb750k_cb750setsticker/ - sorry, dunno what's in that one

Silvers do a couple of different kits - the contents vary (depending on which bike - K0/K1/K2 etc - and which supplier they buy them in from) but the one for my K2 looked like this:



They also sent me a K0 or K1 kit by accident - which I sent back - and from what I can remember, it contained fewer stickers (although I can't remember which ones were left out) and had a different set of Showa shock stickers that were pendant-shaped.  Weirdly, they charge more for that kit than the one for later models. 


Anyways, don't get stung, folks.

It's a good, but not cheap book - particularly if you want information on the early models.

You're unlikely to find any copies under about

Vapour blasting is probably kinder to the surfaces than conventional shot or bead blasting, but yeah, the stuff that gets left inside once the process is complete is very fine.  I've had three engines vapour blasted recently, and no matter how hard the guy who does the work tries to clean them out, I still find traces of the bead/water mix in little places where you really don't want it.  The problem is that the mix is a bit like wet sand - and has the same adhesive properties.

I tend to do a couple of things after my stuff has been blasted to try to get rid of any remaining crap - first, I then leave the parts in a warm-ish, dry place for a couple of days/weeks to allow the water in the vapour mix to dry out.  I then clean out/ream all of the various threads on the cases (you'd be amazed how much crap gets trapped in them and then blow through the oilways and other key areas with compressed air.  After that, I flush the parts with some kind of solvent-type liquid - last time I used turps; the one I'm doing now is going to be washed out with parrafin to see if one's better than the other.  I've tried the dishwasher route before, but unless you're using a dishwasher with no salt in it, the parts will gather salt deposits (and in the cylinders, start showing up surface rust) before the wash cycle has finished.

Mine seem to have come out of all of that pretty well, and I've not seen any traces of anything going bad with the newly built engines.  Incidentally, I had a set of 750 carbs blasted recently and the bodies now look like new.  Just make sure that if you're not going to paint the cases (I don't - never found a paint that's durable enough), coat them in ACF-50. 

The alternative is to find a furniture/metalwork restorers and have them dip the cases in acid.  It takes about a week, does much the same job as a vapour blast, but doesn't leave any residue.

Hope that helps.

Like the vinegar/coke idea.  And IIRC, ketchup can be used like gel for the same effect.

As an alternative, can I recommend http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_186271_langId_-1_categoryId_165594?  Nope, no personal affiliation or connection - it just worked well for me.

I've just had the tank on the '69 SL350 I bought earlier this year resprayed, but stupidly didn't look to closely inside before sending it away.  When I got it back, the exterior looked fantastic, but it was then that I discovered the insides were covered with a layer of rust.  No particularly deep penetration - the tank stood for a l-o-n-g time with some very nasty smelling fuel in it - but there was an ugly layer of brown stuff on much of the insides.

I thought about using the stones/shingle/beads/shot and cement mixer approach, but wasn't particularly convinced I'd get everything I put in out again (the inner spine of the tank is very high - much higher than any other Honda twin I've seen).  So I got hold of a couple of 1ft long lengths of reasonably small link chain and put them in with distilled water.  Once I'd shaken it all up a lot, I drained the water and used a magnet on a stick to get the chains back out.  I thought about using the electrolysis methods I've read about, but decided to try a less radical approach first off. 

So I bought me some of this rust remover stuff and diluted a litre of it with nine of water into the tank . . . fortunately the tank has a 10l capacity, so it's not exactly a tricky measurement.  Following the comments on the Halfords site, I didn't really have particularly high hopes and left the mix in the tank - giving it the occasional stir - for about three days. Well, it worked; without any great effort on my part, we were back to bare metal.  Flushed everything out with tap water, then distilled, then petrol/2-stroke oil mix to coat the insides (it's not going to be used for about a month or so) and it's stayed good for the last few weeks despite having been sat in the shed.  And as it says, it's paintwork safe.

I've since found it also cleans up chrome surprisingly well, although I'm a little reluctant to leave anything that isn't bare metal in solution for more than a day or so, just in case.  I'm now running various fasteners and other bits through it.  Obviously it's not going to help with real bad rot, but as long as you're patient - and have got containers big enough to soak parts in, it seems to do a pretty good job on most metalwork.

Hope that helps.