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. If i roll it and pop it into gear it start right up. I haven't really rode it hard since this started because i'm worried about. Sounds like you have three out of four. Check your valve clearance, check your compression and check your cam chain tensioner. Also, if fuel is literally spraying out of the. We found that if a valve spacer comes loose, and sits in the space holder wrong you cant start it for beans. We finally remembered bluetraxx and another guy had that. No start, cranks fast and tries to catch but no glory. Set the valves, they were barely out of spec (on the tight side obviously). They are now in spec towards the loose end. 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?
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.