I have an 81 XS650 Special 2 with VM34 carbs, PAMCO with E-Advance and PMA.
Bike runs good. The issue started when I got the VM34's and has been around before I got the PMA or the PAMCO, so its not related to those items.
At idle the right cylinder fires steady and strong like a metronome, Bup-Bup-Bup-Bup-Bup
The left cylinder is intermittent like Bup-Ba-BupBUp--BaBup and it is somewhat softer leaving the exhaust pipe.
I have found that if I move every single swappable component from the carbs, including the intake manifolds (boots) nothing changes. I mean everything, all internals, jets, slides, choke, adjustment screws, all but the body itself.
But, if I swap carb bodies the symptom will move. It is something in the carb body itself, at least that is what logic would dictate. But for the life of me I can't figure out why. Something in the casting?
Has anyone else with VM34 carbs had this issue?
Bike runs good. The issue started when I got the VM34's and has been around before I got the PMA or the PAMCO, so its not related to those items.
At idle the right cylinder fires steady and strong like a metronome, Bup-Bup-Bup-Bup-Bup
The left cylinder is intermittent like Bup-Ba-BupBUp--BaBup and it is somewhat softer leaving the exhaust pipe.
I have found that if I move every single swappable component from the carbs, including the intake manifolds (boots) nothing changes. I mean everything, all internals, jets, slides, choke, adjustment screws, all but the body itself.
But, if I swap carb bodies the symptom will move. It is something in the carb body itself, at least that is what logic would dictate. But for the life of me I can't figure out why. Something in the casting?
Has anyone else with VM34 carbs had this issue?
