I've got an Armstrong CMT310 with the HIRO engine. I bought a photocopied manual from Sammy Miller which is little more than useless, I was expecting a proper workshop manual with technical info. The bike starts from cold after a few kicks and will tick over etc and starts first kick when warm, but seems to have very little compression for a 310cc single- I can turn the engine over by spinning the flywheel with my hand- surely that can't be right? I understand the spares situation for these engines is fairly hopeless. Has anyone else overcome this situation? Is there a piston that will fit from another engine? Does the cylinder have a steel liner insert or is it a plated bore. Also any info on carburettor settings would be great.

Thanks,

Mike.

if you have a spark plug in it should be fairly hard to turn the engine over by hand, sounds like you have a top end prob !

It has a plated cylinder, a Kawasaki 700 jet ski piston will fit.

GOOD LUCK

Try Bob Wright in Weston super Mare 01934 510333 ........he had a new Hiro piston kit a couple of weeks ago, not sure if its a 310 or 320 though.

Cheers

Martin

Yes the plug was in it. I'd kinda resigned myself to an engine rebuild. Does anyone know what type of plating it is and where to get it redone (Ideally in the East Midlands). I'll try Bob Wright for the piston, thanks to you all for your help so far.

Mike.