Carb dying in spirals.

[shawnrw]

Walbro 37 carb dying in spirals anybody have any ideas? If I let the carb idle it's fine, but if I give it gas it dies. All other flight modes are fine.

Thanks for any help.

Thanks

[norbertflyer]

Just make sure your kit is properly rated for spirals and your skills are up to date. We've had a few failures performing acro on reasonably modern kit recently. Acro and subsequent kit failure has taken flying friends from us, in the past. Please be careful.

Richard

[Trickyh]

I have heard of this problem happening in spirals with float bowl type carbs due to the bowl emptying during the spiral... No idea why it should do it with a diaphragm type, unless the weight of the fuel in the main fuel line is allowed to drain back into the tank If its ok picking up from prolonged idle in straight and level then it must be fuel line/pump related

Check this webby on the inner workings of the Walbro. They suggest changing the membrane annually...

http://www.aerocorsair.com/id27.htm

Good luck and safe spirals

[ptwizz]

If you're generating (say) 2 G in a spiral, then the pump needs to generate double the normal pressure to get fuel from the tank to the carb. This is true for both float bowl and diaphragm types.

Pete

[bigpapa]

I've recently had this problem too.

I had a small air leak. When doing spirals the pump has to pull fuel harder, which resulted in more air being sucked in at the leak and therefore engine loosing power.

Under normal flying the leak was small/non-existent so it was very hard to find.