Carb and fuel in air hose?

[Hoffman Fisher]

Hi all, I've this listed in another area but I don't know if it was the correct one.

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

[dapper]

Sounds to me like your pilot is too large, hence the spitback, poor starting when hot etc. One good reliable tip is to turn off the petrol just before you turn off the engine, and when re-starting, kick scooter over before turning on petrol to prevent flooding and spitback collecting in the carb bellows. Try a smaller pilot and set your air screw correctly.

[Hoffman Fisher]

Thanks for that dapper, smaller pilots on order, I'll give that a try. Is this a common thing, as the scoot was running fine prior to winter hibernation?

[dapper]

If it's not run for a while, then checking the carb is clean and jets blown through is a must. The oil seperates out from the fuel into the bottom of the tank, so fresh fuel mixed correctly is a must too.