suddenly it started revving up then revving down unless I goosed it to keep it running
It had been runnig very well. I had finely tuned the idle six months ago, But I have been driving it on a very rough gravel road a lot. The other day it began to act up. It would want to die but I could hit the gas but then it revved way up and then started to die. I could keep it going by using the gas each time it revved down. the carb was loose on the manifold and I fixed that but it did not change anything Yjee carb had come oose in the bolt on the manifpld - towad the endigne. Fixred that but no change. What could this be?

