08-02-2022, 10:40 AM
(06-02-2022, 06:30 PM)dchw1975 Wrote: I tested compression with a compression tester and all 4 cylinders came out at little more than 50psi, which seems v low for HC head etc. though I have yet to test the volume of the cylinder head. What should the combustion chamber volume be for an HC head?
Valve clearances are all good though as the head is off I will clean the block surface and valves and then regrind to ensure valve seats are good. The only thing there is that they are very very large inlet valves so the seats are quite thin...
This all started as its seemingly impossible to get it running so that the plugs are anything other than carbon black and I already have it well less than 2 turns of mixture on my HS2 carb. It goes well but also won't rev which is v irritating as you can imagine.
Hi David
Have you tried a hotter spark plug? Champion D21 plugs have vastly improved the sooty nature of the plugs on my engine.
Cheers
Howard