Three quick questions, am I right in thinking that:
1. The M20 primary chaincase cork gasket only requires a smear of grease before bolting up?
2. A solid head gasket doesn't require any sort of sealant?
Hope this isn't a silly question, but this is the first bike I've had that uses a valve lifter, so perhaps someone can enlighten me:
3. I've adjusted the exhaust valve lifter to provide the recommended clearance at the valve, there's no slack in the cable adjustment, but there doesn't seem to be much of a lift when the lever is pulled up tight - there's just enough 'lift' to push the corner of a piece of paper under the valve head and it's trapped when the lever is released. How much of a lift is normally expected/needed?
Scorp.
Scorp I glue my primary gasket to the outer case, then a smear of grease on the gasket that mates to the inner case. That way I can take my case off and on without disturbing/replacing the gasket.
An annealed copper head gasket can be installed dry. Some like to put a smear of grease on it to help it bed or even a light coat of Welseal.
The M20 valve lifter is not the best design in the world. You need to adjust it so that it is clear of the tappet once the valve is shut and not hold the valve off its seat. Only a small lift is required to de-compress the engine. If you are not getting any lift? There must be some irregularities in your adjustment, or the cable. Ron
1) blue hylomar on the chaincase & gasket, high temperature wheel bearing grease on the engine, and just the thinnest of wipes as you really do not want grease in the clutch.
2) Solid copper gaskets go in dry after annealing being disimmilar metals they do not stick together when heated
3) check the hole in the timing cover, they do wear oval and oft need to be bushed.
This is accentuated if owners have them adjusted up way too far.
The valve only needs to be just lifted off it's seat to allow some of the gas under pressure to escape sufficient to allow you to move the the piston without breaking any thing.
When you have adjusted it start the bike and put your finger on the lever in the case. Rev the engine and feel for movement in the lever ( means the valve is hitting it when running ). If you eel any movement then back it off.
My valve lifter is adjusted so slack that the handlebar lever needs to move nearly 1/2 it's travel before the valve lifter contacts the valve.
Another cause can be, (for the valve lifter problem, that is)
If the valves are not original, and the stem it a bit short,
The gap adjusters may have to be extended allot in order to reach it,
And then the shoulders of the exhaust gap adjuster height can be too far up
For the lifter to reach, especially if its eccentric pin is worn out.
