Modern Vespa

Hello all,

now the other evening I was out trying to tune up my carb. It was getting a bit dark and I noticed that as I was touching the fuel mixture screw i would get a very small spark from time to time. I only noticed it as it was getting a bit dark. Has anybody seen such a thing before? if not where should I be looking to track down the cause?

Many thanks
Cheif

I have two scenarios for you. Either you have static electricity built up in your body or the ground from the engine to the frame isn't the best. Hope that helps.

I agree with B-Rob. Try running a 'redundant' ground from the motor to the body.

thanks for the advice chaps. I will take a closer look at the engine grounding.

do you think this would make a difference to the running of the engine?

Depends on the type of ignition and where and how it is mounted. It is helpful when the year and model are indicated.....

I can't really think of how there could be a spark doing what you described. Static possibly but I assume the screw driver had a plastic handle ?

In any case, you can't have too many grounds.

some even ground their exhaust!

The screw driver had a plastic handle.

the model is a 1981 p125x with electronic ignition. no battery. not electric start.

Curious. Can you replicate this again ? I don't see how there could be any type of current between the screw driver shank and the grounded mix screw but, like a plastic comb, I guess there could have been static electricity in the handle.

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I was surprised myself. I will have a go at it again one evening this week. I need to go to a quiet spot so i don't annoy neighbours with my engine noise after dark.

Besides have 4 wires attached to the motor, clutch, brake, 2 gear, you think a 5th one will do the job?

Dunno but I have wired the oil drain plug

I just had a thought, perhaps I am not letting the dog see the rabbit here. We have some history.

Originally the scoot had a battery. When I had the frame repainted the guy offered to put a new loom in. I accepted, but then some months later when i got around to the final build I discovered he put a loom in for a no battery set up. At that point I decided to just go with it.

Then, a couple of weeks before I had to take the head cover off, a some wires disconnected and it took me ages to ger it working again. One was the wire from the ignition, another was to the parking light. When i was trying to get it to work, I had a few faulty. One was that the parking light was working, but the blue dashboard was not (although it worked on the big lights). I fiddled around with the connections to the light to get it working.

Edit: I just thought of something else that puzzles me. On the key ignition. There are several connectors on the back. Currently only 2 are used. The thing is they dont seem to be related or connected to anything else. So when scoot is off. The switch is connecting to one wire, but it doesnt appear to make a connection to anything else. Then when scoot is on, it switches to the otehr wire, but again, that connects to nothing else. So i cant see how the hell this is actually working.


I'm wondering now if I may have reconnected something in such a way that the electrics seem to work but with a grounding error.