My husband is a class A mechanic. the timing chain on a friends moto 4 is broken and needs to be replaced. the only problem is... how does he line it up correctly to ensure the timing is correct? the owner thinks it is an 84 225cc my hubby needs to know where the timing marks are, and how they should be set... mean while, i'll keep searching this site there is no mark on the cam sprocket just the dow pin / key way... please help, i'll keep editing each time hubby comes in from the garage with more info... thanks

 

well, the engine shop that had the bike prior... had put the cam sprocket in backwards.... friggin loonies!!!

 

well, that was alot easier! turns out the timing was 180 out... easy to figure out when the cam sprocket is put on the right way.... thanks anyways guys!

 

alrighty... well here it is... the problem is still the same... the bike cranks over, will idle for a couple of seconds, backfire, and then die ... he's cleaned the carb, he's cleaned the jets, he's got good spark... the compression is good 145psi, the valves are good, the timing is fine now, WE ARE STUMPED! any suggestions please! please! please!

 

Try tradebit.com to see if you can download a manual for it. Got one for my 87 moto 4 80cc for $5
142 is considered low compression on them and 175 is average. No idea on the 225 though. He has tried a new plug?
Ken