Fast Idle Speed

[Maladjusted]

My Vespa T5 Classic starting ticking over really fast on Sunday. I've lubed the throttle cable both ends and it's made no diiference so I don't think it's that. Takes a few kicks to start now whereas previously it would start first time. Strangely if I pull the choke out, the idle speed goes to somewhere near normal, but push it back in and it revs itself up.
Engine etc is bog standard T5.
Any advice please?

[LI150]

You have a air leak somewere

[Maladjusted]

You have a air leak somewere

Thanks for the reply. Where are the likely places for the air leak? I'm pretty clueless at fault finding unless it's fairly obvious.

[Jack221]

The most likely is the clutch side oil seal, hopefully it is jsut something simple but sounds like you have some of the symptoms. How does the gearbox oil look?

[servetakid]

I'd start by cleaning the carb. A small blockage in a jet can cause poor starting and fast idling, plus it's the simplest thing to rule out before replacing seals or tracing an air leak.

[ducksta]

Drive side oil seal if you have not changed anything lately, if you have been tinkering retrace your steps.

[LI150]

Clutch oil seals, cylinder head, base gasket, carb gasket, loose exhaust it could be any I'm afraid it's a process of elimination

[Juan]

The carbs are known to warp on occasion so don't rule that out before you start looking at duff seals. Most likely to show up when the motor is warmed through.

[Maladjusted]

Thanks for the replies everyone. Looks like I'm starting with the carb and then working on from there.

[Maladjusted]

Drive side oil seal if you have not changed anything lately, if you have been tinkering retrace your steps.

Not tinkering as such, but jacked the back of the scooter up on Saturday to change the rear wheel. It was running fine until Sunday morning so what's the likelihood of this causing whatever the problem turns out to be?