Hey guys I just picked up a 08 yfz450 for cheap! Problem is it will not go into neutral so I took the sellers word that it has compression.. got it home pulled the plug, hit the starter and the piston does not move but the bike lunges forward while spinning the starter... where should I start looking?

 

If the piston doesn't move but crankshaft goes round, it has probably "thrown a rod" so engine out and a total strip and rebuild, not going into neutral is the least of your problems.

 

thanks that was my thought as well I just didn't want to tear into it if it was something simple.

 

You could just take head and cylinder off to find out what it is like in there, before removing engine from frame. I often have to do this with seized engines, if piston hasn't broken up, it is just a new piston and rebore, if piston has broken up, it is engine out, strip down and hunt the shrapnel.

 

Yeah its out and in a million pieces. Had a athena 480 kit that looks like it was over reved and grenaded took out the jug rod piston not sure about crank yet. Need to split the case and look for more damage. Head is still good surprisingly.