Went to fly today engine has been working great for close to a year however today was different. First let me say that I had a fuel tank leak at one time and fixed it (supposedly) had about 6-7 flights since tank was fixed no problems. Today engine quit on take off after restarting engine ran good on level but when doing vertical test emgine hesitated and quit, Any ideas what to look at? It also has new glow plug on engine and Yes I changed it to try and it still quit on vertical any help appreciated.

It sounds like your high speed needle needs a LITTLE bit of adjustment.

What I do is: After the engine is running and the glo clip disconnected, I peak the engine and then back off about 300 rpms. Now, with the throttle still wide open, pick the plane up and point it's nose straight up. The engine should continue to run with little or no change in rpms. If the engines "sags" then tries to die, it is too rich. Close the needle valve ABOUT 1/16 - 1/8 turn. If the engine speeds up (most cases), it is too lean. Open the needle valve ABOUT 1/16 - 1/8 turn.

With the plane level, go to idle, then to wide open to clear the engine and repeat the test until the engine has little or no rpm change.

Things like the amount of humidity in the air and/or the temperature can affect the high speed needle valve setting, HOWEVER, it should not take more then 1/8 turn to correct IF THE ENGINE IS PROPERLY TUNED. If it is taking you more than 1/8 turn to correct the problem, your problem is somewhere else.

Since you had the tank out recently, I would suspect the tank and the fuel lines. Perhaps a line is kinked.

If you still have the problem after trying to readjust it as Campy suggested, take the needle valve out and flush fuel through the carb and clean the needle off good the reinstall and go through the adjustment Campy uses. By the way when reinstalling the the needle valve I usually turn it in till it JUST touches bottom then turn it out 1 1/2 turns and it normally starts so I can do the adjustments. ENJOY!!!!