Biffo
XS650 Enthusiast
Have just had the first run out of an '81 SH that I am restoring. Idling was shocking, with loud "popping" from the left exhaust. Checked the exhaust system for leaks and all OK, but noticed that the left carb intake was wet with fuel. While poking around I found that blocking the pilot air jet hole with my finger immediately gave perfect idling. Take the finger away and the problem is back, with the engine revs rising and falling dramatically as well. Have dismantled and checked the carbs. Float heights are good, floats are intact, jets are all clear. Both pilot jet mixture screws are 2 turns open. All ports appear to be clear. Any ideas, anyone?