RE: New Hanger 9 p-51 mustang **Trainer?!?**
I'm not to sure about the whole pressure thing, never had any problems and I live around Denver (Mile High) and run my motors without the baffles. I was stating previously that that my final HSN adj. is 4 clicks rich from peak rpm, this is after I test it nose up. If I was to leave it without checking nose up it will cut out almost immediately after take off. A pump just might be the way to go but like I said, I don't know enough about them as I have never had any problems. Then there's my RCV motor, it spoils me as it doesn't even need back pressure to run at all. Something to do with the design of the motor pulls the fuel into it, ran it for over an hour with no pressure line on the stand and it never even hicuped.
My advise would be as I was taught, tune it on the ground then final tune it with the nose up on 2 strokes, 4 strokes are a little different.
Shane