recently my last flights my engine stops at just below mid stick as I throttle up, it has never done this before. It seems to do it after I have landed and refueled and so on. the engine is warm. I do have a throttle-jockey governor on it but that kicks in at about 1/4 stick so I don't think that could have anything to do with it. Any ideas?

Try a new glo plug before doing anything else.

Also did you replace the stock clunk line with a good aerotrend line? The clunk line in the raptors becomes brittle, faster with higher nitro.

I have installed new glow plugs and it seem to help, I forgot to add that it is really tough starting unless I have the idle way up high. I have not tried adjusting the mixture control screw because it is almost impossible to turn and I really don't have a very good screwdriver for it.

Impossible to turn because of your screwdriver (time to invest in a screwdriver man) or because it won't turn?? It could be your mixture, which one is hard to turn? What engine you got? Yeah all of the stock fuel line has to go asap remove and replace it all.