I am assuming a tricycle gear. How does the wheels turn, any binding? If you pull full up, will it lift the nose or isn't it getting up that amount of speed.

If you can swing that 11-6 at 10,000 rpm, you should have plenty of HP in the engine. I doubt that removing a baffle is going to make any difference.

like said before, check the balance. unless it is grossly nose heavy, it should fly.

If you can find a large piece of cardboard, ply wood, etc. try using it for the first part of your roll out. It will give you and 8 foot runway that might allow you to get up enough speed to get on top of the grass. Have a helper hold the tail and go to full throttle then release the plane .You should get up about 1/3 the speed needd for lift off by the end of the board, and have enoght speed that you are not trying to lift the plane out of the grass with the wheels.

Just to be sure it will fly though, I would take it to the field with the paved runway and see how it does there.

One last stupid question, but I have to ask, are your controls set up OK, IE up elevator is really up?

Don