perhaps an obvious answer?

[vacancy]

just got an '80 xs11. every so often i'm feeling slightly heavier vibration and a loss of power. i cycle down to first, pull over, pull out again - and everything's fine.

huh.

-jon

[TopCatGr58]

Hey there Jon,

Well, not so obvious an answer!! Need more info, you need to try a few things as well. What RPM's are you running in and in what gear when it happens? You could be just lugging the engine, running too low an rpm for the gear, like in 5th at 2,500 rpm!! Would downshifting to lower gear, but keep running along instead of stopping fix it?

Could be pickup coil wires starting to crack/fail, could be vacuum lock in gastank/cap, could be vacuum/centrifugal advance mechanisim slightly sticking, bad gas, vapor lock in fuel lines, loss of vacuum to petcocks causing loss of fuel flow, dirty or partially clogged carbs, etc! Hope this gets you started, come back with more info on what helps and what doesn't.
T.C.

[beechfront]

not sure if this applies to your situation, but i've noticed on my bike that there are two rpm ranges of about 200 rpm around 4000, & 5500 that there is slightly more engine vibration. in my case at least, i don't feel it is a problem.

[vacancy]

thanks

thanks. the previous owner was running it lean. maybe fuel starvation? good to have some other suggestions, though.

-jon

[Dragonrider]

Wouldn't hurt to check your fuel tank vent . . .