Hello

A friend of mine is having problems with an R1 bike carb conversion on a 2LT Pinto engine.

When the engine is cold it starts and runs ok without the choke connected.

As soon as it warms up it starts to splutter and struggle to rev out,also blows black smoke from the zorst.

He has checked the mixture screws which were 3 turns out from the stop and has now changed them to 2.5 turns from the stops and it runs a little better however it is still not right.
It is a Bogg bros manifold and carbs.

Does anybody know what the mixture screws should be set at as a starting point.

He lives in the West Midlands so taking it to Bogg bros would be a trek.

Any help would be great to get the car drivable and then it could be RR tuned.


Thanks

Sounds a bit daft I know, but are you sure the choke is off.They are usually spring loaded, sound like its well rich.
Steve.

Sounds too rich, can't start mine unless I have the choke/enrichment fully on and don't touch the throttle. Idle screws I think are at about 2 turns. As the previous suggestion check the choke arrangement is actually working also what fuel pump is being used. Could be over pressurising and flooding, I use std pinto mechanical one with a pressure regulator set at minimum 1-2 psi max. is all that is needed.

It is too rich. Normally, when the engine is cold, it runs too lean because the fuel condenses on the cold engine walls. You need a choke to richen it up so that it will start. You put the choke in when it warms up.

You have got it so rich that it starts without the choke only because half of the fuel you put in is condensing out. As it warms up, it burns more and more of the fuel.

Turn the idle mixture screws more lean (clockwise I think)

Thanks for the reply guys

I will pass the suggestins on so he can try them.

Is there anyboby in the West Midlands who would be willing to discuss the problems by telephone if i passed my friends number on?.

Thanks very much