Petter A1 Flywheel not turning full revalution

Inherited a Petter listed on plate as A1 5 BHP 2000rpm Engine number 524249 from a deceased engineering friend of mine. I am a retired NZ motor mechanic and after checking for siezed valves proceeded to checking the gear train, no problems found.The engine is missing its govenor arm and outer spring. Someone has recently had the head off,decarbed but engine has not been run since.I have checked through the internal inspection plate all ok with pump rod moving up and down untill flighwheel stops at half turn in each direction.Have not removed the magneto (Wico A series) as yet so don't know if the govenor weights etc are ok.

Any suggestions appreciated before proceeding further.
Bob.

I'm afraid another strip down might be in order. It is difficult to know what it might be without closer inspection. Could be the rings sticking in the bore, tight big end shells or the valves set too tight. Whip the head off again and see if that reveals anything.
DanBoy

I am clutching at straws here Bob, and welcome by the way, but has the timing case been removed at all? I only ask because on some engines that I have encountered (not Petter's) the crank web can foul on the camshaft lobe if it is out of time on the valve's, only a suggestion but might be worth checking if nothing else comes to light. Otherwise I can only think that something may be jammed in one of the gears? Good hunting!

Pete.

It is difficult to pin point with out know all the details, has the mag been off? has the engine been stood a while? Does the engine turn over with the head off? The only thing is get your ear to it and listen if you can hear a klunk and trace where it comes from. Let us know how you get on.

Stu.

i agree with the others above
i would rip the head of first and see if theres a object on top of the piston
like a bolt or nut can sumtimes be dropped in the plug hole by mistake and stops full revolution of the engine,
when the piston is on the way up and item
siting on piston hits the cylinder head ??
or some thing in sump, and crankshaft ballance weights or comrod hit it on way around
other than that the rest above are possabilitys too
STRIP IT AND SEE IS THE BEST THING TO DO
thanks kev

Stu and all that replied which was appreciated.

Found that camshaft gear was fouling on the casting attached to mag drive gear.The jamming was caused by a misplaced washer which was wedging out the mag housing from the gear train backing plate. At point of jamming the backing plate could be seen to flex. All free now but valve timing is out. Is there an anomoly with my engine number on plate as it does not appear on the chart.

Will upload photo once resized showing where gear was jamming.

Bob

Great news you've managed to sort it, looking forward to seeing the pictures.

Stu.