Vintage Dirt Bike Q & A

Hi, guys trying to get some answers here first off got a basket case 89 yz 250 in-which i have (with some trial & error) rebuilt from the ground up. trying to put the finishing touches on it but just can't get the timing correct . i'm thinking because i swapped out the crankrod assembly to a 90 that i need to do the same with the stator plate already ordered part hopeing this will correct the problem. symptoms include rpms hanging (NOT RUNNING LEAN & PAST LEAK DOWN TEST) & power-band just not hitting as hard as it should powervalves are perfect as i said went threw this whole bike with a fine tooth comb ! i also noticed the stator pick-ups are spaced differently on the 90 then on the 89 i also am not sure if the flywheel is a different size for an 89 & 90 ?i can't seem to find much help maybe one of you guys have so in-site on the matter any help would be appreciated thanks Dan