Tickover when hot

[brucemclane]

I have an LI150(175) that ran like a dream for 18 months, but recently won't tickover when hot! I run a jetex 22mm an AF clubman exhaust. I sent the barrel piston and rings to AF Rayspeed and they replaced rings. I've rebuilt the engine but it still won't hold the revs when idling. It just stalls unless I keep accelerating when I need to slow down or stop,any ideas please Nigel

[rossclark]

Would worth cleaning out the carb particularly the pilot jet circuit.

Also might be worth asking the mods to shift this thread to the Lambretta Help section.

[brucemclane]

How do I get it moved to the help section??

[Scooterlam]

Contact one of the mods
They have their names in green.

[coaster]

Have you changed the plug?
Changed or cleaned the airfilter?
If it has points have they been gapped?
Is the choke returning fully?

[Toddy]

Moved as requested

[brucemclane]

Thankyou for your help and advice, cheers

[MickYork]

1st option would be the choke sticking.

A blocked exhaust along with the other suggestions may also be the problem.

[johnnyXS]

sounds like the mixture might be too rich at idle.

Idle is controlled by a combination of the pilot jet, the air mixture screw, the slide type ie cutouts if any and the slide position set by the throttle stop screw....so you will need to tune all three of these on the carb at idle


I would suggest fitting a 45 pilot which should be adequate .(50 is probably more appropriate for a 200cc) and try tuning the idle with that. If your idle air screw needs to be screwed nearly all the way in obtain a decent idle then your pilot jet needs to be changed to a 45

Is your Jetex fitted with the 150cc slide (the one with the cutouts) or the 200cc plain slide .


First I would check and Adjust your air screw in 1/8th -1/4 turns together with your throttle stop screw (slide setting) until you can get the fastest consistant idle with the lowest throttle screw adjustment .Screw the air screw In to weaken and out to richen the idle mixture.
If your idle air screw needs to be screwed nearly all the way in obtain a decent idle then your pilot jet needs to be changed to a 45 or your slide changed to a cut out 150 type