Modern Vespa

I have a problem. When my 125 LEADER engine (2 valve) gets warm it coughs before it picks up from idle. This becomes an issue when trying to make a quick getaway from the lights, as you might imagine.

Went in to have the carb needle replaced as advised by the dealer which made no difference whatsoever and cost me £200.

Has anyone else suffered this and managed to remedy it?

Cheers!

£200 squids bloddy hell thats a bit steep. How much does he charge for labour? that job shouldn't take more than 2 hours IMHO and thats at a very relaxed pace.

did he clean the jets and give the carb a good blowout, seems like your idle jet maybe a gunked up.

Who is your dealer? £200 for a carb needle? That's a 1 hour job max.

How many miles does your ET have on it. Can you describe the symptoms exactly? Does it sort of bog down and perhaps judder on take off?

My ET4 did this and I was convinced it was the carb, but it turned out to be a worn clutch. What was happening was that the leading edge of the clutch had worn away allowing metal to metal contact on take off. This disappeared once the clutch was fully engaged. Happened at 12,000 miles.

In my case, it turned out that the spark plug wire was not solidly screwed into the cap. It looked fine, which is why I didn't find the problem until I came across it while working on something else.

When I screwed the cap back on properly, the problem went away.

PS: I have a leader engine...I'm "assuming" the set-up is similar on pre-Leader engines?

With a £200 bill they must have replaced the whole carb.... if not OUCH indeed...

If they just changed the needle, they shouldve replaced the atomizer tube as well, as both parts wear together... so replacing one without the other is pointless...

I would also get the valve clearances checked if its not been done in a while, a slightly tight inlet valve will give a similar fault.

That'll teach me to post a thread without proof reading first! Should have read £100 - £50 for the needle and £50 for the labour.

Battery hasn't been too clever recently - wondering if it might be causing the stutter on take off... It's a like a misfire only the plug, lead and coil have all been replaced!

Nipping into London on it tonight for a good run so we'll see if it clears. Could almost sense a drop in power when accelerating hard from a 30mph ish cruise too.

Hey ho she still starts first time - I'm just a perfectionist that won't sleep until I've found a cure!

Cheers for your all your thoughts!

Think I've worked it out - the battery is a bit weak and it seems to only be happening when the headlights are on, or I've been sat at the traffic lights with the brake light on. Maybe the spark needs to be extra big when you first twist the throttle from idle.

Will properly test this theory later and MAYBE shell out for a new battery!

Cheers,

David