Help me troubleshoot my No-Start

[scooterfan]

Sounds like the valve floated and made contact with the piston possibly due to over rev.

Very interesting theory. I’ve never heard about anything like that. I guess this would only be possible if something came loose during over- revving ?

[CROSSBOLT]

"Valve float" historically a problem with single springs, cured by double and triple springs, cam profiles and desmodromic valve trains like Ducati. Honda solved the problem with carefully tested (cut and try) spring rates and a little math. Other causes of valves open when should be closed are sticking and keepers popping out. Usually related to poor maintenance. Also usually damages piston.

[scooterfan]

"Valve float" historically a problem with single springs, cured by double and triple springs, cam profiles and desmodromic valve trains like Ducati. Honda solved the problem with carefully tested (cut and try) spring rates and a little math. Other causes of valves open when should be closed are sticking and keepers popping out. Usually related to poor maintenance. Also usually damages piston.

Thanks ! I never over-rev anything - so I did not know this can cause problems.

To my understanding there are a few hard-riders on this forum. It might be worthwhile knowing whether over-revving was causing a problem in this case. Maybe all of us should be aware of a potential problem.....

[JayPortland]

Update.  I ordered a replacement valve.  I'll try to install it over the weekend.