Honda-SOHC

Hi again. To me that would confirm that you need a sealant at key points if not all (I've always covered total area) on any gaskets pattern or otherwise.

These are my reasons:- Honda clearly designed (original gasket proves it) to have some type of sealing additional to the gasket material around the oil ways.

I don't believe that sufficient torque can be exerted to do it totally dry with no additional sealant of some sort (copper rings, factory applied sticky-bits).

If you don't have that original spec of gasket OR something superior to it you'll have to use a substitute.

You can't increase the torque without stepping outside the original design spec, anybody that knows anything about the engineering design process will tell you that looking at this design (layed down in 1967 ish) was an absolute masterpiece then and still is an example of how to make a first off reliable engine from scratch; just one example is the stud design that is waisted (thinner) in the centre than at the threads to give equal torque load over the whole length and cross-section of each stud!!! also how the bottom threads are buried down into the casing so that the load is pulled from further within the material again to spread load indicates how thorough the design team went to work.

To me, the risk of using Blue Hylomar is only to avoid ANY loose sealant floating around as it survives in oil. The rest is all upside, as previously posted (by rigwit?) this stuff is seriously good.

With a nice new tube you can get a really thin spread coating onto the gasket, it even looks and feels like the original coating when it's dry.

Be interesting to see what your barrel / head inspection shows, let us know.

Maybe a bit too enthusiastic design appreciation there, maybe should be filed under "soapbox" but they are really good...............really.

Rigwit, it must be like working on swiss watches with the bikes after things that size. At least you put your skills to good use with some fun engineering on the bikes although I guess you can go anywhere in a TBM!! 

Yep I noticed that in our family "bike" a VW diesel, it will do something like 40miles more to a tank on some brands than other low sulphur stuff and I heard that the pumps last longer with sulphur so aim to buy that and AVIA fuel I bought in france was the best for range that I've seen (apologies for off topic disesiel! discussion).

I guess this may not affect SOHC stuff so much but may impact on newer Injected bikes with pumped fuel supply.

That's a good point what can you coat it with? some older car tanks were painted on the inside so there must be something that would suit.

Can you still use the vinegar on your chips?

I read somewhere the other day about wrapping the fuel tank in foam, putting fine gravel inside then leaving to rotate while sucured in a cement mixer to clean the inside (was it on this forum). So if you add vinegar then a thorough clean! I geuss it's only like a gentle shot blast I suppose.

On another weird note. Worked with an old guy years ago who swore by chewing gum to stop a leak in rusting fuel tanks as a get you home fix and it does work!

Hi and welcome to the forum.

You seem to have been quite thorough in working at any causes. It's possible that the floats are touching something inside the float chambers, are the floats all the same or are they handed to fit different carbs? if there is a difference it may be very small.

Agree that if valves will shut off fuel with light pressure then they should work ok.

If you turn the carbs upside down and blow through the supply you should be able to hear / feel if they are different with float bowls on or off.

We used to use cutting wheel on off-hand grinder to make one flute in allen bolts, then clean threads with needle file to de-burr and voila a good thread cleaning tool. And you can make most sizes cheaply, they don't need to be hardened as you are usually only cleaning something out not cutting into casting.

I know it's off topic for this forum but those P6 rovers are nice. There was a manual white one with period minilite wheels at newlands corner the other month, very nice.

I don't know if you recall but I've got an original spec blue colour 750 F2 stored at my place for a freind so if you need any details give us a shout, no dismantling though. It has a genuine Yoshimura pipe on it that looks really nice and an original standard set with it.