I have a new thunder tiger pro 46 that I put in an alpha 40. After running about 4 tanks through it, and breaking it in, it ran great. I then swapped the engine over to a hanger 9 f-22 raptor after having a mid air collision with the alpha. Now it runs good and will stay running except when the plane is tilted up. In about 5 seconds the engine will speed up on its own and die. It does this every time the plane is tilted up. I can tip the plane back on its tail while it is on the ground and it will do the same thing every time. I am wanting to do a madien flight on this plane this evening but dont want to risk it until i figure this out. I have no clue at all. Anyone have any ideas?

Not much to go on but it's obviously going lean. My first suspicion is in the fuel tank area especially since this is a new install that has never worked correctly. Since you have never had a long run I suspect all of your observations were done with a near full tank. My thoughts lean toward you having the engine feed line hooked up to the vent tube. The vent tube may be "in" fuel when level but "out" of fuel when tipped back.

that would be my guess also

Either that or the clunk line has a pin hole or came off in the tank.

That shouldn't have an effect until down to 3/4 tank or so unless the end of the line is floating high in the tank. I got the feeling that this was at near full tank levels.

All good suggestions. I'll add another. Make sure the klunk is no closer than 1/4" to the back wall of the tank.

Dr.1

It was on a full tank. But this is a brand new tank that came with the hanger 9 plane. You would think that it would be set up correctly from them. But i will check it out. thanks.

NEVER assume anything. There was a thread last week where a guy had a NEW Nexstar RTF with an incorrectly factory set up fuel tank.

It will if you raise the nose up.

He sais he was lowering the tail while on the ground or tilting the nose up, NOT that he was picking the plane up and pointing it at the Sun. I was answering to the conditions HE was going through in which case I was correct.

I have a number of tanks that have the stopper near the top of the tank and just tilting the airplane on its tail will bring the stopper out of the fuel in a full tank (knowing that a full tank does not mean that there is no air at all left in it) But not knowing the style tank used in the F22 PTS I will concede the point.
I would suggest however a complete inspection of the tank and all the fuel lines.Never count an any manufacturer to get it all right and sadly alot don't.

After inspecting the tank the clunk was touching the back of the fuel tank and when slightly tilted went into the very corner of the tank. It was so close it looked like it could possible starve the engine of fuel. Also it was hard to see through the tank but when I took the stopper out of the tank the supply fuel line was disconnected. So not sure if it came off while I was taking it apart, or if it already came apart. I ran out of time today but will shorten the intank line up and secure it better so it wont come off. I am sure this will fix it! Thanks for the great tips.

I have a NexStar and had this same problem. The instructions directed to set up the lines according to their color but they were not plugged in the right way.

It may have been your prior post/thread that I was recalling.

Keep in mind that often these planes ae being assembled by people who don't know an airplane from an avacodo. They just stick parts together at their workstation. NEVER assume, ALWAYS check!

Dr.1