Scooterotica

Some thoughts please Gents.

I'm trying to help out a friend of a friend who has recently bought a Lambretta from Vietnam.........

There were initial problems with it starting due to a crap choke cable and a 22mm Jetex sleeved onto a standard
"150" inlet manifold. All now sorted due to the application of a new choke cabke, a remade Scootopia 22mm carb and the correct inlet.

Bike starts 3rd kick and runs sweetly.

The owner is not "Lambretta knowledgable" ( we all have to start somewhere), and now advises me that when hot and approaching junctions and lights etc, the engine races on when putting the bike into neutral.

He switches off and rekicks the bike and all is well until the next set of lights etc.

I have not had a look at the machine yet, and my thoughts purely on his description are:-

1) throttle cable/ carb sticking somewhere?

2) air leak??

I am inclined to think the throttle is sticking somewhere rather than an air leak due to the fact that the bike runs sweetly and restarts OK.

Anyone got any thoughts?

I just don't fancy removing the stator housing etc.

Chris

Agree with either air leak or something sticking.

He needs to get his hands dirty and the next time it does it, don't touch the throttle, switch off, take the bellows off and see if the slide is too high/sticking.

With the air leak i'd be inclined to look round the carb'/manifold area first. When idling spray some brake cleaner/easy start around the suspected areas and see if the rev's change.

To quote: I'm trying to help out a friend of a friend who has recently bought a Lambretta from Vietnam.........

Stop spending anymore money now.

The above should have been your first clue, the carb issue the second clue, and the apparent air leak or other your third.

I would be extremely weary of continuing any kind of repair or even riding it.

If you know a thing or two about lambretta's then go over to his and inspect the scoot thoroughly. I would personally start with tyres, rims, brakes and associated mechanisms and bearings. If there's anything untoward thats your next warning.

As a test, consider whipping off the side casing and inspect chain, clutch etc for anything odd.

Im not suggesting that all eastern imported scooters are complete bodge jobs, but generally they are.

If ive misunderstood anything apologies, but a quick google of lambretta + vietnam will clear anything up.

scooters are great but not when they put your life in danger.

It wouldn't be something really simple like the throttle cable being too tight would it? Ask him if he stands up while he's at the lights.

thats what I think it is- we'll see next Monday.

I think you are on the right lines with the cable being too tight, possible an issue with the routing into the cable adjuster.

I had similar some years back and it was an air leak..

inlet or flywheel seal Tim?

Mine was the flywheel seal..... could see the oil as soon as I took the flywheel off.

would it not be constant if it was an air leak ?