Question about 1979 Yamaha XS 650 SF

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80 xs 650 hesitation and exhaust "popping"

I have 80 xs 650 special. i have an intermittant hesitation from around 3500 rpm to 4000 rpm sometimes after that. its almost like i'm running out of fuel like a hiccup. it's kind of a jerking. sometimes i can "power" through it sometimes not. i'm thinking something with the carbs? any help would be great. also a little "popping" from lefthand exhaust on deceleration doesn't seem to be leaking air past carbs to cylinder.thanks.

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Most likely the carbs need cleaning and adjusting. You may want to richen the A/F ratio when you do it. They are set really lean from the factory. I would go 1/4-1/2 turn out on the A/F screw.

Posted on Jul 22, 2009

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