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Fast Idle Speed
Posted: Tue Nov 15, 2016 12:55 pm
by 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?
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 1:56 pm
by LI150
You have a air leak somewere
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 2:08 pm
by Maladjusted
LI150 wrote: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.
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 3:42 pm
by 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?
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 4:34 pm
by 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.
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 6:31 pm
by ducksta
Drive side oil seal if you have not changed anything lately, if you have been tinkering retrace your steps.
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 8:13 pm
by 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
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 8:38 pm
by 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.
Re: Fast Idle Speed
Posted: Tue Nov 15, 2016 9:00 pm
by Maladjusted
Thanks for the replies everyone. Looks like I'm starting with the carb and then working on from there.
Re: Fast Idle Speed
Posted: Wed Nov 16, 2016 1:14 pm
by Maladjusted
ducksta wrote: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?