Carburattor adjustment? LD150 1957

[GianfraCh]

Hey lambrettistas!

I am finding it hard to warm the bike up properly. it starts at a first.. second kick and then it does not stay running too long.. could this be solved with adjusting the carburator? I believe the spark plug is good as I bought a new one and checked the gap and seems completely fine. couple of weeks back the bike switched on quickly too but stay running longer.. only thing that has happened since then was that I snapped the throttle cable but finally changed it and seems all good. I made sure It had good lube inside and even changed the outer cable! I did also put the new spark plug (B7HS) any idea what this can be or any advice?

Cheers!

[jbcollier]

Carbs are adjusted when the engine is fully warm.

There is no way that you bought an NGK plug and it came out of the box gapped at 20 thou. Buy a spark plug gauge and gap it correctly. At the very least, fit the old plug and see if that solves your problem.

[GianfraCh]

Hey JB

Thanks for the reply. Yes I will get a gauge and properly check. I will try to adjust the screw when the engine is fully warm, I think that was my mistake there. I adjusted it slightly with the engine not really warm and I think after that I could never really keep the bike running at minimum. So that adjustment has definitely made a change as I cleaned the old sparkplug with a bit of fuel and tried and was the same. =/

Do I have the have the engine fully warm and running and adjust it there until it keeps it on at minimum?

I appreciate the help in advance!

[jbcollier]

Engine fully warm. Best time is after a ride.

The angled spring loaded screw adjusts the speed. The horizontal screw adjusts the mixture. Turn in the idle mixture screw until it is lightly seated. Turn it back out 1.5 turns. This is the base setting.

Get it running and warm.

Adjust the idle speed screw so it idles ok. Turn the idle mix screw out until the engine starts to slow down. Back in until the engine is going the fastest. If it starts to slow, turn the screw back out. Trim the idle speed screw as necessary. Once you have found the point of fastest idle with the mixture screw, turn the mix screw in another 1/4 of a turn.

Now drive the scoot. How does it "pick=-up" off idle? Smooth? You're good. Hesitates a bit? Turn in another 1/4 turn on the mix and try it again.

[GianfraCh]

Thanks JB!

Amazing help!! =)