LCGB Forums

I am trying to get my head around which atomisers and slides are the richest and where the bleeding starts between pilot/ slide/ atomiser/ main. Does a guide exist?

If no such guide exists, May I ask:

Is a 5914-2 slide richer than a 5914-1?
Should a 7895 slide only be used with an SH2/22?
5899 atomisers. Which is the richest?


I have obviously used SH carbs before but not on an engine that has been significantly tweaked. That’s why I am asking

Hi Paul
Hope you are well
If you search "jetex" on the forum or 22mm jetex, there's lots of info on atomisers & slides for SH carbs that should help you(on or around page 7)
Cheers Mark.

Btw the Vega looks good, nice work

Thanks, Mark. I shall sit down and go through it later

All the best.

There you go http://www.ilambretta.co.uk/carb/jetting.jpg

HxPaul wrote:There you go http://www.ilambretta.co.uk/carb/jetting.jpg

Thanks for the reply. Yes, I have seen this. It is in Sticky’s and the Lambretta Workshop Manual. I am after a guide that would help you jetting a carb from scratch on a non standard engine.

I can see that the 5914-1 slide is richer than the 5914-2, for example. I can see this as the size of the cutaway is smaller on the 5914-1

message sent

What spec motor? I've played a fair bit with the SH range of components so may be able to help.

There may also be old forum threads available, in which I discuss the non-linear rich vs. weak delivery of the atomisers.

Adam_Winstone wrote:What spec motor? I've played a fair bit with the SH range of components so may be able to help.

There may also be old forum threads available, in which I discuss the non-linear rich vs. weak delivery of the atomisers.

Hi, Adam. It’s a 4 speed Vega with original barrel given a modest tweak by Chiselspeed. Exhaust with baffle removed and larger diameter tail pipes. Airbox has had usual holes drilled to increase airflow.

Thanks to Hullygully

Didnt the old Lambretta Tuning Guide cover jetting? it certainly covered the exhaust mod. I have a copy but not able to get to it until Sunday

coaster wrote:Didnt the old Lambretta Tuning Guide cover jetting? it certainly covered the exhaust mod. I have a copy but not able to get to it until Sunday

I have two copies. Can I find either though