Engine won't rev - I'm at my wits end !!

[bristolmod]

initially a blocked exhaust which has subsequently caused overheating/ damage to the top end somewhere??

Chris

[johnny LIS150]

if at first it ran well without problems I'd be inclined to think that there isn't anything wrong with the original carb jetting

If you have cleaned the carb and jets and ran it with the air filter off and you can see that there is clearly air and fuel getting to the engine then it must surely be the electrical /ignition system ? maybe a poor earth , electrical short ....weak spark, timing out ?

Id be inclined to check the compression before tearing anything down . Easiest way is to get someone to push the scoot in second gear whilst you walk alongside holding the compression tester in . Settle on say 8 or 10 revolutions so that each subsequent compression test can be compared later and you can be sure that maximum compression has been reached on the tester. If there was a serious compression issue you would feel it on the kickstart anyway so I would say its unlikely.

I would check everything thoroughly to make sure you haven't got any poor connections or shorts and use spray some carb cleaner or WD40 etc around the inlet whilst its running to see if you have an air leak.

[johnny LIS150]

hey Weston did you ever get this problem sorted ? what was the problem in the end . ?