Problem starting, but narrowed reasons?

[Hoffman Fisher]

Hi all,

I'm sure that aspects of what I'll say here are covered somewhere in the archive, as it's a lambretta and therefore someone will have encountered particular issues before.

I've had issues with starting from warm, this is only recent since it's winter hibernation, the scoot was not in use december through to now and when started it wouldn't idle, it would just die, don't get me wrong, I could take it for a short spin but would have to keep the revs high to stop it dying. So had done the usual checks and changes, i.e. two new piston rings and gasket, spark plug, fresh petrol, gear oil change, new inlet hose. I thought then that it may have been a timing issue and have now remedied that and it starts as usual with 1st or 2nd kick and as mentioned above loads of revs just to keep the engine ticking over.

Further tinkering and tampering has now narrowed things down to this: petrol spit back in inlet hose and when the hose is removed it will start when warm on the 1st or 2nd kick. what's that all about, anyone encountered this and remedied this before.

Here's my set up; LI150 - Jetex Carb (I know they can be ropey, but It's been fine up to now), Pilot and choke jet are 50, main jet 118, float needle has been checked and is fine, float bowl and needle are fine and do what they're meant to, carb has been cleaned, so you could eat your dinner of it.

Any help would be appreciated. Any questions for clarification purposes please ask and we'll get to the bottom of this.

Cheers

HF

[bristolmod]

I've had Jetex carbs work fine for years and then suddenly "go off".- possibly crap in an inner drilling somewhere??

Is it possible to substiture another Jetex for your present one to see if that miraculously cures it?

If you are near Bristol I've got 4 or 5 you can try.

Chris

[Hoffman Fisher]

Thanks for the offer but I'm across the water in Northern Ireland. Cheers