Yfz 450 Cranks But Wont Start - Next time you try it, crack the throttle open just to make sure the starting fluid/air mixture is getting past the slide. If it still won't fire, you are either way out on timing, or you. Pulled carb off, checked all jets and verified everything was in working order, checked valve clearances and cam timing, verified that there was spark, and checked coolant. Everything i looked at checked out good. There was 1 intake valve that was at the top end of. I am trying to pinpoint a starting/running issue. I'm thinking it's a carb adjustment issue, but not sure. What are the factory hi/lo settings on the carb? Is there a brake/clutch. Have you tried starting fluid when it won't start? You're sure that it does have continuous strong spark when it won't start? I have pulled the spark plug and. I've got a problem that's kicking my ass on my yfz. It cranks but i've got no spark. My neutral light isn't coming on. I just replaced the relay with a genuine yamaha one so that. Charge the battery overnight on a 2 amp charger and see if it cranks in the morning. If it does test the rectifier and stator to make sure it is putting out 13. I installed the new starter and no change, i did pull start it and it ran great and it will start when the motor is warm with the start button but when the motor is cold it will not turn the. It cranks and cranks,but no start. Here is what i know: Quad ran great a week ago,minus battery dying. Carb is getting gas, as i drained the bowl when it got flooded. After flushing oil, changing plugs and cleaning the carb the bike would crank fine but just wouldn't seem to fire other than the occasional backfire. I decided to dig deeper and. 2007 yamaha yfz 450 will not start.
Next time you try it, crack the throttle open just to make sure the starting fluid/air mixture is getting past the slide. If it still won't fire, you are either way out on timing, or you. Pulled carb off, checked all jets and verified everything was in working order, checked valve clearances and cam timing, verified that there was spark, and checked coolant. Everything i looked at checked out good. There was 1 intake valve that was at the top end of.