- Joined
- Apr 22, 2011
- Messages
- 3,337
- Reaction score
- 395
- Location
- Princeton, Texas
- First Name
- Gary
- Last Name
- Waugh
Okay peeps, I need some ideas!! A friend of mine bought a non-running CRF450X about 3 weeks ago, we removed the engine, saw that the valves where burnt out and there was a lot of scoring on the barrel and piston. We purchased a new barrel, rings and a piston, we then purchased kibble white SS valves, lapped the valves in and assembled the head. Checked the play of the big and little end bearings (all was within spec) so we put the engine back together and put it back in the frame. We cranked it over on the electric start (with the auto decompressor disabled and we are seeing about 100psi, I completely cleaned the carburetor and confirmed the jets are clear and blew out all passages. The accelerator pump is Lso working correctly. So I know we have fuel and compression. I have removed the spark plug and cranked the engine over and we have a very healthy looking spark, so I figured the engine would start. But we crank it over and there is not the slightest signs of life!! I sprayed a load of easy start in the inlet tract and after a few seconds of cranking got a good bang in the exhaust system like a backfire) but still no signs of any life.. i am now struggling to think what could stop this engine from trying to fire up. The carb has all stock jets and setup, I reconfirmed the camshaft is timed correctly (it is!!) so any ideas what might be amiss? I can only think the spark is occurring at the wrong time, but even then I would have expected some signs of life (kick back, popping, something) but we still have nothing, the engine just cranked over smoothly and shows no attempt to start..
All ideas or suggestions greatfully received as I am starting to pull my hair out..
Gary
All ideas or suggestions greatfully received as I am starting to pull my hair out..
Gary