18 replies to this topic

[Simples]

Could well have been gravity if on a slope ? SU carbs don't go 'out of tune' - sure it's not sticking throttle cable ? Or sticking choke cable ?

Definately not, it's float level related I presume, there was a lot of petrol!

[Nightrain]

Sounds like a worn jet to me, take the dashpot and piston off and have a look at the brass jet. Could well be oval due to the needle wearing on it, which is down to the spring loaded needles fitted to these carbs.

[Sherlock]

I had similar problems with a waxstat carb, particularly with the emission test, it works on engine compartment air temperarure, not engine temperature, which is a very bad move because as soon as you open the bonnet, the air cools & the mixture richens. I replaced the waxstat element with a solid metal spacer, no more problems with tuning or emissions.

[Simples]

I had similar problems with a waxstat carb, particularly with the emission test, it works on engine compartment air temperarure, not engine temperature, which is a very bad move because as soon as you open the bonnet, the air cools & the mixture richens. I replaced the waxstat element with a solid metal spacer, no more problems with tuning or emissions.

Thanks for the suggestion but it's not a waxstat, think it's float jet issues but not sure