Scooterotica

Right here goes....just had a engine rebuild 500 miles a go...no expence spared on the insides...mb 225 stage 4 tuned ( etc etc)...been running like a dream and really have had a big smileon my face,but yestaday comming home from work,tootling along in a traffic que,it suddenly just stalled,no bangs or cracks.
checked the usual...spark plug (nice brown colour),but still swapped it. got a good spark,so went onto the carb,carb jets nice and clean...and fuel flowing nicely,asked at the local scooter shop and they reckoned it could be the cdi,so i swapped that,still same...i really am just learning at the min,but am not thick and understand the basics,so declined the offer of it fixing at the shop,as i really want to be able to fix probs like this.
Whats worrying me is.the scooter used to be a right b@5t@rd to kick up,but now its not as hard (compression),ive just tried to start it and i got a big backfire if that helps anybody diagnose this....anyway,ive a feeling that something top end as gone,but how could this be at 10 mph max...please dont shout,like a said am learning...plus am a hard b@5t@rd anyway,,and would maybe drop on ya at a rally....aha aha...all help much appreciated..and i really am impressed at this place.....(wish theyd hurry up we that watercooled lammy tho)...ride safe,with clutches well covered...

Take flywheel of and check your woodruff key is still good

Cheers Mark....(reaches for the sticky manual)

off to shop it goes...cheers for trying to help mark..but i aint a fkin clue.

I must admit I also thought woodruff key when I read your post but if it isn't that then I wonder if the spark you are getting is strong consistent, i.e. if you take the plug cap off, does it jump a gap of 5-10mm with a nice blue spark. If not, it could be your LT coil breaking down. If you havn't got a multi-tester it wouod be worth you while getting a cheap one and checking the resistance of the LT coil (Green and White wires from the stator) and the pickup while you're at it Red and White wires). It's all in stickie's book

cheers coaster...swapped the cdi..i have a nice blue spark...jumping from plug to casing on the scoot...fuel is going thru....the plug is wet...just had one loud backfire...nothing else..thanks for your time.

I'm certainly no expert but could it be the timing....

cheers for the help pal....the timing is perfect,and asnt moved....on to the head now....

half a curly wurly it's woodruf key.

Well hung...am still waiting to get the flywheel off....extractors are like rockin horse s**t in Barnsley...off to mb tomoz...il pass the bet on to another feller ,who says its either piston rings/head gasket... :fb: