I have an issue with a Coleman 125 I bought for my son. When starting it up I cannot give it throttle. When I do the starter stops and the display goes blank. Sometimes the display resets as if I had just turned the key into the on position. Once I get it running it's fine but as you can imagine its hard to get it going without the ability to give it throttle especially on a cold day. Any suggestions on how to troubleshoot to the cause of has anyone seen this before?

 

Probably a loose earth, so the throttle cable is becoming the earth wire. Very dangerous, as it can start to melt, then stick open when you are riding.

 

I didn't even think about that being the issue. I'll trace the ground down again and check that throttle cable out. Thanks!

 

I didn't find anything wrong with the cable. Could the valves need adjustment?

 

It is the earth wires from battery to frame and engine that need checking. Check the positive from battery too. Valve adjustment won't stop the display going blank, even if it is not an earth problem, you definitely have an electrical one. Could even be battery flat or bad.

 

I'll dig into it deeper this Saturday. Thanks!