opjose - thanks. With my old SK90 engine, i would have problems with a dead stick, similar to the person that posted the same issue with his Funtana 50. I cut and pasted your reply to my email for quick reference.

Basically, when i would go vertical, the engine would run fine. But when I throttled back from full to say mid throttle while the model was in vertical position, the engine would stall. I checked the tank and did a presure test and it was fine. But just in case, I ordered a new plug and stopper kit for the tank. I'll switch out all the fuel lines too.