Hi Guys, my M91 has been running well for the last few months, however it decided not to restart after I had been running it for 15 minutes.
There was no compression for the first time ever. after a number of checks I decided it must need a new piston O ring. I fitted the replacement ring on the lower groove which i remember reading here somewhere. While i was stripping the engine I decided to replace the crank needle bearings with oil filled bush's AM.0812-8.PL . These are a great fit and all that slop and rattle is gone now.
However after reassembly I cant get the engine to fire? Good spark, good compression . I have tried adjusting the ignition and the valve timing but no luck?. Can somebody on here, please let me have the ignition firing point BTDC, and also the point the exhaust valve opens .
I have put the engine aside for the moment as I am pretty frustrated with an engine that is not over complicated.