Please Help!!!

[grizzlyboss91]

Ok so I just bought a 2003 400ex that has just been rejetted and had a 11:1 dometop piston standard bore. The boy that I bought it from said after he did this it would run for a short time and then kick itself out of time, however it will not run at all at this time. I checked the timing and it is in time. When I turn the motor over it will wind for a second then hit and wind some more and hit again. Could anyone tell me why it will not crank haha. I currently have the head removed and now would be the perfect time to fix it.

[drew416ex]

It may have bent some valves causing it to not have enough compression to start. As for it jumping timing, the tensioner might be messed up.

[grizzlyboss91]

Ok thanks what should i look for to check for bent valves and what should I check for to see if the tensioner is good?

[drew416ex]

You can pour gas into the ports and see if it leaks out of the valves. Take the screw out of the tensioner. Then you can stick a small flat blade screwdriver in the hole and turn it to the left. The tensioner should loosen, and when you let off of it with the screw driver it should spring back.