Drive Side Air Leak?

[Lamaddict]

I have such an annoying problem that's driving me to despair. Scoot starts and runs fine for a few miles then seems to suck air in from somewhere, it then starts over reving and stalls, even back fires, then starts easy, pulls away okay, then the same again. Seems like an air leak somewhere but I can only pin point it to the drive side seal, everything else has been checked and changed apart from the fuel tap and flywheel!!! I mean everything.

The question is, if the leak is from the drive side seal, wouldn't it burn the oil out of the gearbox? I've also had to stop the scoot revving to oblivion by blocking the tail pipe on the exhaust, and if the seal was leaking wouldn't that not stop the revving? On the rebuild, I used the gasket and high temp silicon to make sure the seal wouldn't leak. I can't see it as the problem because of those things mentioned but I just don't know.

I didn't want the grief of a total strip down, unless someone has any other ideas?

Totally lost on this problem.

[B-Race Tuning]

Blocked (or no) fuel tank breather hole?

[garry inglis]

On my recent build doing a leak down test it was the brand new champion spark plug it would not seal so changed to ngk and no more air leak


Sent from my iPhone using Tapatalk

[mick1]

A leak test will be much easier than a total strip down........although if it's the drive side seal you may have to do that

[Muppet]

fuel supply me thinks

[Daggs]

Is there a chance when sitting on the scoot the fuel pipe kinks and restricts flow. When you get off to restart, the pipe is unkinked.

[Chris in Margate]

You need to do a basic leak test. Go and buy a bicycle inner tube (wide one). Cut it in half opposite valve.
One end on inlet manifold, the other on exhaust down pipe. Pump to about 7 psi and wait. Soapy water finds bubbles.

[Lamaddict]

fuel supply me thinks

Thanks everyone. Seems like this is the problem, it took over an hour to drain the tank. I had the same problem before but was convinced it was sucking air in some where.

How does it rev to oblivion with the symptom of an air leak ? I'm guess that with no fuel it sucks more air through the carb?

I've not read the whole thread about newly made OMG fuel taps but this is one. The last time I had a similar problem the tap seems like it was blocked up a bit by crap from the tank but I'm wondering if the tap is crap. I'll put another tap on a feedback.

[fluff34567]

Check the flow once the cap is removed

[Scooterdude]

Yes they can block, take it to bits and give the holes a good ole poke with some wire then blow out with an air line, failing that I've got a Scootopia one here I can sell you