Posted Tuesday, August 31, 2010 @ 08:34 AM  

I'm also in the UK with an RF3 but I've never had problems with carb ice. I have only once seen it during a ground run with the cowlings off and that was just a little skim of hoar frost on the butterfly. But I've also ground run extensively in very damp conditions with the cowlings off without it forming. What engine is in yours? Is it the stock 1200cc or maybe the 1400cc?

The obvious thing to check is that your baffles are effective so that what air ends up below the engine has been warmed.

Posted Tuesday, August 31, 2010 @ 09:46 AM  

A quick tip.

On all airplanes it is bad practice to run your engine for any extended time without the cowlings in place.

No cowlings = no cooling (and of course no carb heat).

The eventual result of overheating can be a broken exhaust valve, or that the aluminium of your heads will change its structure, becoming soft. This allows valve guides to slip out of position, leading, like a broken exhaust valve, to complete engine failure.
The big problem is that such overheating does not usually cause these problems immediately, but a considerable time afterwards.

I have no idea how hot your engine needs to become, nor for how long you can get away with it, because it's something I only ever do if there is absolutely no other way, and then for the absolute minimim time.

As to carb icing, it has been mentioned elsewhere on this forum. I try to avoid it by making all prolonged descents with power still applied.
All you have to do is think ahead, and lower your nose to increase the airspeed and drag a few miles before you reach your destination.
This apples for all airplanes, not just Fourniers, and helps to prevent shock cooling too.
Think like a tug pilot.