3 replies to this topic

[Cyborgpl]

Hi everyone. This is my first post on the English forum so please bear with me technically and linguistically.In Poland, unfortunately, we have a very small forum because Mini is a great rarity. I have a mini with an hs4 carburetor. I always have the mixture too rich. I noticed that the float was leaking and sank. After replacing the float, the mixture is still too rich, and in addition, when I remove the carburetor piston after turning off the engine, when the needle comes out of the jet, fuel leaks under pressure from the jet (such a single strong sip). It's normal or something is wrong???
Please help ... what can i check???

 

[Gilles1000]

Hello and welcome here.

What do you have for fuel pump? Mechanic or electric? aybe it's pumping too much to the carb?

 

gilles

[nicklouse]

Welcome 

 

here is a link to the SU tech info that you might find useful to refer to.

 

https://sucarb.co.uk...ion-adjustments

 

Changing the float will not affect the mixture but will stop extra fuel entering the float chamber. Extra fuel eating the chamber can be caused by three things.
The float not being set at the right height or being punctured so can not close the needle valve. 

the needle valve being worn and not shutting off the fuel.

the supplied fuel from the pump is at a too great a pressure. (Greater than circa 3psi).

But result of this is fuel being pushed out of the overflow on to top of the float chamber.

[cal844]

It sounds like the carb is working OK, replace the needle valve and float in the float chamber.

To lean your mixture you need a needle changing or modifying (possibly both).

Because of your location I have no idea if anyone offers an SU carb tuning service (AC Dodd is the man you need for the training required)