[mrothwell]

I just got a new to me 2003 crf450r. It has newer valves and runs great. I took it out yesterday for climbing and single track. It ran great except on the 2 steeper hills it cut out. It feels like an electrical cutout, not fuel because it doesn't stutter, or bog, it just cuts out like I had my thumb on the kill switch. It happened a couple other times in hard acceleration, but most of the time it ran great. Any ideas what would cause this? The bike starts easy, idles fine, pulls hard. I just need to find this issue.

Thanks.

[crfsonly]

welcome to CRF's Only. check your kill switch. these are notorious for this very thing if not properly installed or damaged. also check your ground is solid. replace the spark plug to eliminate this as a possible issue. if it's not these and it is something electrical it will be more challenging to resolve.

ken

[mrothwell]

being that it happened 2 times on relatively steep hill climbs, is it possible to be a fuel issue? maybe a float level to low, or something like that?

[crfsonly]

could be the float level or other fuel related issue if it is only happening when the bike is not on flat surface.