5 replies to this topic

[mergedown]

I posted a question a while back and received an amazing response outlining the steps to help me adjust the mixture on my carbs. I had assumed it was running a little rich, but now Im not sure.

I understand that when you push on the lifting pin and it increases and stays increased...its too rich. If it increases and then almost dies...its too weak. Mine definitely decreased on one carb, but doesnt increase at all. The other would cause the engine to die almost immediately with still no increase. I made some adjustments and the motor doesnt seem to die, but still cant get it to replicate what its supposed to do. Do I just need to keep adjusting?

[Retroman]

You need to check that at fast idle they are both drawing the same air....before adjusting the mixture

 

Its a bit if a faff but with the air cleaners of and some hose....

 

Listen to each carb to make sure each has the same noise, the hose has to be in the exact same place on each carb mouth.

 

Its then a case of adjusting the idle screws so both carbs sound the same.

 

Then the mixture can be set accurately at a fast idle.

 

Then turn each idle screw back the same amount to set the idle

 

All of the above assumes there is no linkage affect from the choke, and nothing binding or sticking

 

You sometimes find the legs on the linkage need adjusting

[mini_man96]

A Gunsons colourtune and carb balancer will make the process a lot easier aswell!

[Spider]

As they do seem to be running well lean, check you haven't got a vacuum leak too and this could even come from the carb spindle bushes.

[mergedown]

Thanks everyone! For some reason I’m intimidated by this process as I’m afraid I’ll mess up the tuning and it won’t run the same. That said, I’ve received a lot of great info, so I’m just gonna go for it! Worst case, I’ve got some great resources in our local Mini club, so I’ll reach out to them if I get stuck.

Thanks!

[gazza82]

I tried a carb balancer on an MGB and gave up after a while. When for the 'listen through a tube' method in the end. (I'm convinced the balancer was faulty)