RE: Engine bogging at high pitch
You need to get a better "accomplished pilot" to help you or get him to really take a look at what you have. The pitch needs to be set up with a proper gage and the best way to tell if the motor is tuned right is by temp on the back of the head. Low end adjustment is by pinching the fuel line and see how long it runs. There are many posts about this here. I would disconnect the gov until you get the basics right. Where are you located? Maybe one of us is close....