NO STAMINA

[Edwin1973]

I'm working on on my 6th build and have encountered a problem I've never dealt with before. The build is a CDH Power Custom frame, 80cc motor, NT speed carburetor, CNC head, Supercharged CDI, NGK B8HS 5510 spark plug. It runs great for 10-15 minutes at 35-40mph, but then the motor dies as if it was out of gas or.has no spark. After cooling down it will start right back up as if nothing ever happened. I've changed the magneto to a high performance one, replaced spark plug, replaced carburetor, tried running straight pipe for exhaust (just ordered expansion chamber muffler to try), checked gaskets......I AM STUMPED!

What am I missing? I have a lot invested in this project and at this point I am frustrated beyond belief! Any suggestions?

 

[curtisfox]

Gas tank cap venting is plugged, filter plugged. Check it all out...........Curt

 

[Bikeguy Joe]

curtisfox Well-Known Member for the win!

 

[Tony01]

Gas tank cap venting is plugged, filter plugged. Check it all out...........Curt

Yup got me stumped once

thought this thread was about something else

 

[Edwin1973]

New filter. Gas cap seems fine, but am looking for replacement to be sure. I thought it might be the gas, but I'm running the same gas in one of my other bikes and its running fine.

I have a high performance magneto, but am wondering if it may be getting overheated. Do they make a temperature resistant magneto?

 

[Greg58]

Edwin if you think the coil is getting hot try running it with the cover off, be sure to keep your pant leg clear. The wind of riding at 35 will more than enough to keep it cool.

 

[Edwin1973]

Thanks man, I'll give that a try and see what happens.

 

[Tony01]

Check your gas tank shutoff switch. Could be clogged.

 

[Edwin1973]

Gas tank cap venting is plugged, filter plugged. Check it all out...........Curt

After trying everything else I could think of and mentioned in thia thread, I took the rubber seal out of the top of gas cap and cut out a gap about an eighth of an inch and replaced it. Put cap back on tank and rode for almost an hour with no problems at all. Hard to believe some thing so simple could cause such a headache.

Thanks!