I bought a 79' XR75 2 weeks ago. At 3/4 to full throttle the bike falls flat, spits and sputters.
I adjusted the timing, points, valve clearances, cleaned the carb, replaced the plug and the bike still does it. However, if I remove the air filter the bike runs much better with only a slight hesitation once in awhile during extended wide open runs.
I checked the compression, it was 85 psi. Added a bit of oil to the cylinder and the compression was 100 psi. The bike doesn't smoke though. The manual says the compression should be 170 psi, which seems high.
Could low compression be causing my problem? Or should I look elsewhere?
Thanks in advance.
I adjusted the timing, points, valve clearances, cleaned the carb, replaced the plug and the bike still does it. However, if I remove the air filter the bike runs much better with only a slight hesitation once in awhile during extended wide open runs.
I checked the compression, it was 85 psi. Added a bit of oil to the cylinder and the compression was 100 psi. The bike doesn't smoke though. The manual says the compression should be 170 psi, which seems high.
Could low compression be causing my problem? Or should I look elsewhere?
Thanks in advance.