Scooter died

[ricardo59]

Hi all
Was out on my vespa the other day when it suddenly died on me and wouldn't restart. managed to push it home and tested for spark which seemed ok. could anybody tell me what would be the next step to figure what the problem is? It has cut out on a few other occasions but i managed to catch it wile still moving but the last time i was going up hill. It is a vespa px 125-180 with a 30mm Dellorto and PM big bore exhaust...I was going to have retuned as it was very heavy on fuel and seemed to chuck fuel back out of carb. Help!

Read more: http://vespa.proboards.com/thread/6004/ ... z4LvAPhHrU

[mick1]

three options: Electrics, fuel or compression.

Seeing a spark is a fair indication but not conclusive. Maybe change plug and cdi. I'd also check if the woodruff key is ok
Is fuel getting to the plug ? also quality of the fuel, maybe worth emptying the tank and putting some more fuel in.
You've not mentioned compression so I would assume it appears to be ok. Maybe worth rigging up a leak tester to check.

I've mentioned the cheap quick test but it maybe something more involved....keep us posted

[ricardo59]

Hi yes you maybe right because it just died no spluttering or anything like that just it just came to a halt.
thanks for reply, will keep you posted.

[Morgan]

Think you can rule the fuel out if there was no spluttering. Looking likely to be electrical, cdi or stator would be my bet.......fair call on the woodruff key though, I've had that happen before.

[paul d]

I'd check the length of the fuel hose from the tank to the carb. It needs to be just long enough to allow access when the tank is pulled up from the frame. Ultimately I'd fit a standard carb setup with maybe a 120-125 main jet if possible and you can work up or down if need be. You could take off the exhaust from the barrel and shine a light into the port to view the condition of your piston. You can also tell if the rings are seized into the grooves by twisting the fan and watching to see if the rings are moving and not stuck solid. If the piston has heavy scratch marks you can assume it's been seized at some point and might point to a compression problem. I hope you don't lose hope.

[ricardo59]

Thanks for comments lads...I'll keep you posted

[fraserp200e]

I had a similar problem. Ended up being the cables coming from the stator breaking down / earthing as they came through the casing.

[ricardo59]

Hi all
Right i've done a few checks and it seems to be getting a spark and there is fuel getting to the plug...now wether the sparks strong enough or there's sufficient fuel entering the chamber is a different matter? so still at square 1. when i dry the plug and kick start a number of times with spark plug out and fuel off to clear chamber it fires once then nothing. Thought about stripping the but it looks a ball ache to get the throttle cable on and off so mite start with a new CDI unit? what do you think guys?

Read more: http://vespa.proboards.com/thread/6004/ ... z4M38Cuswv

[paul d]

Have you tried bump starting it? It sounds like your choke mightn't be working properly by the way the scoot fires after alot of kicks and then stops but I know from how you described the bike earlier that you've some other issue. Maybe a blocked jet or loose carb or manifold. If you can push it in first gear you'll be turning over the engine at a good pace. Even a scoot with poor compression will try to run. Also a scoot with a blocked pilot jet will try to run. You mentioned alot of oil around the engine in a previous post. Is the carb firmly attached? Manifold ok?

[ricardo59]

Yes tried to bump start but not even a back fire. if there is a blocked jet could it be the main jet preventing it starting or is the main jet not involved in the start up process? Its either one of the following, weak spark,not enough fuel entering chamber,too much fuel entering chamber....the problem how do you determine which one it is. I'll take main jet out clean and note the size if that doesn't work get new CDI and HT cable