What compression is required on a Villiers Lightweight 125cc Type 512H
All,
I have just acquired a 1964 17" JP Super Power Mower which is 99% complete. However, no compression, or spark. The stator plate assembly has been tested, condenser was dead and duly repaired by John Cruse. Removing the head showed a stuck exhaust valve...
I don't have a compression testing kit (yet), but what psi should I be looking for to get the mower started - assuming I can free off the stuck valve...I expect to have to grind in the valves in due course...but can worry about that later....first thing is to get the mower running. Secondly, what torque should be used for the head bolts?
No mention of any of the above in Villiers handbooks - but owners expected to "de-carbonise" the engines as part of routine maintenance. Finally, any recommendation on solutions to free off the stuck valve - I suspect it may be stuck because the mower was sat around for a while...modern day fuels may have gummed it up? So what dissolves any old fuel residues? Carb cleaner?
All advice gratefully appreciated.
Tony
Forums
Thank you Wristpin.
Thank you Wristpin.
Stuck valve has now been freed and removed using carb cleaner and WD-40. Both valves have been ground and all is running freely. Stator plate has been repaired with a new condenser and fully tested. Carburettor has already been cleaned - full of old fuel residue etc. Time to rebuild!
Tony
Don’t forget the valve
Don’t forget the valve clearances. 2-6 thou on both. I’d aim for 4-5 as they tend to close over time.
I expect to have to grind in
Muddled thinking there! Get the valves right first . Remember VICtor, valves, ignition, carburettion - in that order - saves a lot of time and back tracking. Compression - I don’t think that a figure has ever been published. With the valves done and a new head gasket , if it has a “lump” you should be ok.
Head bolts - the book says 120lb” for the 512 and 515H