21st Nov 2017, 03:51

During the late 60s and early 70s, my 2 strokes went from the X6 Hustler to Kaw Avenger to a Suzuki GT550 triple. On the 4 stroke side I had a CL450 Honda and BSA 650. Both the Avenger and the GT550 would outrun either 4 stroke on a normal day, but all the 2 strokes had similar trouble to yours with high altitude or very hot temperatures. Ran in a stupor, like they had overdosed until a plug would foul. Must be an oil in the gas thing.