Freezing SU carbs

anaxemurderer · Post by **anaxemurderer** » Wed Jan 16, 2008 3:50 pm

I have a rrc with a 3.5 running on two SU HIF carbs. The guy i bought it from rebuilt it/set it up and it was running very well.

Now having lots of problems. Big loss of power and backfirering when throttles let off. Particularly bad when driving back home after offroad events. Will gradually lose more and more power but then sometimes it will pick up again.

Mechanic guy i was talking to reckoned it could be the carbs freezing up. It has no form of heating on the intake, but why should that be a problem now when it was fine before?

Anybody got any ideas? I'm quite keen to get it tuned and balanced properly, will that help?

Nick

Darkspeed · Post by **Darkspeed** » Wed Jan 16, 2008 4:12 pm

I would check the following your fuel lines, fuel tank breather, fuel filter, fuel pump pressure.

Cheers

Andrew

ChrisJC · Post by **ChrisJC** » Wed Jan 16, 2008 4:44 pm

Could be water in the 'lectrics. Does it still do it after some dry offroading?

Chris.

Post by **katanaman** » Wed Jan 16, 2008 5:13 pm

If its carb iceing switching off the engine for 5 mins or so and re-starting would solve the problem (it lets the carbs warm up) if it doesn't your problem is elsewhere.

stevieturbo · Post by **stevieturbo** » Thu Jan 17, 2008 12:05 am

carb icing is also very easy to see. You can actually see ice forming on the body of the carb. In extreme cases, the throttle can actually freeze if sitting cruising at a steady opening for a while.