Trouble shotting an XR75?

Question

I cleaned out the carb, relaced the spark plug, checked the air filter and did a compresion check. It blew 150psi. It started when I primed it with start flud. It had little power and would not idel. My brother said it has been like that since he put rings in it. Could he have got the cam timming off? How do I check? What elese could it be?

Answer 1

Check the points & timing.
Adjust the valves.

Answer 2

make sure you cleaned the slow jet because it is a big factor in the power. the big and the slow jet have a hole down the center try a hair from a wire brush it works well. take them both out of the carb