iflynething,

Have you sorted out your problem yet.

I had a similar problem recently. Cleaned the carb, replaced the fuel lines. Checked the fuel for contamination, none seen.

Still same problem.

It ended up been water in the fuel. You could see small balls in the bottom of my fuel container. Checked the heli fuel tank, same.

Ive since adjusted the fuel pickup in my fuel jug to position off the bottom, so it cannot suck out these water balls. When the fuel is nearly empty, you can check the fuel then and use it if it looks OK. Otherwise keep it for cleaning.