LCGB Forums

Hi,

I have a french mk3 1957 ld my and i am trying to start it after years of being sat.
I think there maybe a ring gone as the kick is so low down when starting does anybody know what compression i should get when testing.

Regards

Adam

I've never tested the compression of a D engine. I would guess it would be lower than what a series 3 engine would produce due to its lower compression. So perhaps 100 psi? I usually test compression by "feel". If there is good resistance when kicking over, it's good. If you can kick it over easily with one hand, not so good.

All that said, your comment that the "kick is so low down when starting" makes me think you should disassemble, clean, check and re-lube the kickstart mech.

Hi Adam,

I am no pre-57 expert, but the position of the kick start engagement is unlikely to reflect whether the rings are broken or worn.

To be honest, an old machine that has been left standing is likely to have worn rings, and this might be the reason why the machine was left alone for so long.

Have you tried bump-starting the machine, thus by-passing any issues with the kickstarter? A couple of pints of fresh petrol in an empty tank would also benefit the process. And check that there is a good flow of fuel into the carb, as crud may have accumulated in the tank.

Hi

I am getting about 50 psi on the compression gauge, As for the kick start it felt harder to kick down a few weeks back and I tried to start it again last night resulting in a back fire.

Regards

Adam

If you are getting a full stroke on the kickstart and the engine is spinning nicely, then 50 psi is low, very low.

Hi so regarding my engine compression the kick start is in line with the legshield floor pan before it gets any comptession. Do you think this would be the rings then?

Regards

Adam

Sounds like you need to strip it and check all measurements and tolerances.

rings might be gummed up with dead fuel, bit like treacle toffee hence zero compression,

I always strip old engines I never try to start them or try turning them, oilseals can be as hard as rock and cut the crank, crumbly and split, rusty springs dropping straight into the bigend or wrecking the bore and piston. Bores rusty and full dust and dead spiders