QuestionI will start with the spark plug, it has a white electrode and black on the outside. I have a vacuum tuner and the right side looks good (golden brown plug) and good vacuum. the left side is showing very low vacuum with the white plug. the motor seems to hold rps just off idel, but seems to idel just fine. I checked for air leeks by spraying brake cleaner by the intake boots between the carbs and the cyl. head with no effect.the bike has filter pods and free flowing exhaust. some of the jets have been changed to accommodate this change(both carbs are the same). I have not been able to do a compression check or check the valves.
AnswerSteve,
Have the carb jets been cleaned?
Is the left carb getting a good fuel supply?
Check the fuel valve for flow.
Check your carb vacuum diapragm rubber for cracks.
Have you checked the valve clearance?
Tight valves could lower your vacuum reading.
I suggest doing a compression check first
to see if the cylinders are even.
If the compression is low, try a bit of oil
in the cylinder and recheck the compression.
If it goes up it may need rings, if it
stays low, maybe a bad valve or valve seat.
