wont start after rebuild

i just had my 450 rebuilt and when i went to start it for the first time it would not start. i do have spark fuel and compression. i need some suggestions

Not even a pop? If you really have all three, spark+fuel+compression and absolutely no combustion is occurring, it seems like your spark timing could be the only thing that could be wrong.

Cam or ignition timing is most likely off or the new valves are not seating for enough compression and ignition to allow starting. :applause:

I had mine rebuilt last winter and she fired up with the e-start on the first crank cycle! :bonk: I was pumped because that was the day before a long weekend ride down south with the midwest boys! :cry:

I just rebuilt mine. I finished it this morning at 3am and I was so nervous that I screwed something up because I was so sleepy that I fired it up at 3am. Only for a half a second. I waited until this morning at 8am to really run it.

Mine fired up on the second kick. If yours is not running. Would say what has already been said. Cam timing or spark timing. What was done in the rebuild? And, if you had it rebuilt have them fix it. Many times when something is wrong the person who screwed it up will know exactly what they screwed up.

Good luck.


I had the same trouble.

After a rebuild mine wouldn't start.

So I set the mark on the flywheel, and checked to see if the punch marks on the cam sprockets were facing away from each other. They were off a couple teeth. I re-set them, and it fired 1st kick. :applause:

thanks guy i am going to take back to the guy that did the rebuild so he can look at it

OK it seems that there was a shim on a ex-valve that somehow got stuck side ways in the bucket and was holding the valve open so it would not start , so i really did not have compression when i said i did. also do you guys know why wisco says not to use there ring in a crome cylinder,when you order a top end kit these rings come with the kit and they have to know that the bike you are going to put them in has a crome cylinder

Wiseco does not know what cylinder your putting there rings in. They can only assume what cylinder your putting the rings in. Your cylinder should be nikosel (nickel and silicone coated aluminum). It may even be Cast iron if it had a sleeve put in.

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