Topic: LMT carb 56 progression

[bimmerbaz]

Hi guys,

Just been out in the paddock testing my mower . I have put a modified LMT carb on it with an adjustable jet. It seems to run well and i have a narrow band oxygen sensor hooked up just for kicks.
 So when i progress from idle to main jet it puffs out a bit of black smoke (RICH MIXTURE). I have opened up the idle air bleed and vented carb to atmosphere externaly. This rich mixture causes a slight hesitation and my thoughts are that i need to cange the progression air bleeds in the main jet.
 I know that most keep carb secrets close to their chest but just thought someone might point me in the right direction.
 If i rev it hard it doesnt have the flat spot, i gues because the air is already moving fast enough to overcome the rich mixture.

Cheers

Baz

[bimmerbaz]

Can no one offer any suggestions?

Baz

[2nstoys]

My modified carb is the same. I always run a little rich. Puff of black when it has no load, but great on the track. You will never feel the hesatation in a race.

[bimmerbaz]

Thanks for the reply, must be a rare problem as no one seems to have any suggestions.I am racing this weekend so will see how it goes.

Cheers
Baz

[Burwell555]

Any race application that requires higher rpm will run a rich mixture. It may sound dumb, but it needs to be fat on the bottom to have enough fuel on top end. My 44 intek comes close to watering your eyes if you adjusting it while its running at idle, but it runs great on top end. When it was set to idle nice, it would break up and run out of fuel at around 3800. I just kept leaning it out progressively until it would hit the rpm I wanted