Tach problem

[81flatside]

i got the bike a couple weeks ago. the guy i got the bike from said that the tach worked last year now it only revs to 2 grand and comes to a stop, once the r's go below 2 it works like normal. i opened it up and looked for pinched wires and found nothing any common problems out there?
by the way its a 81 xs1100sh

[81xsproject]

Probably just it's time. You can clean all the electrical connections and try it again. That's the first step.

PS we love to hear about carbs around here. So, if your running flatslides we would love some more info (with pics )

[TopCatGr58]

Also while it's running, put a voltmeter on the battery and check for the voltage going above or close to 14.5 volts at ~2500 rpm. IF the voltage is only around 12 or less, then it's not charging, and the tach runs from a lead from one of the 3 legs of the charging circuit. It's rare for the windings to crap out, more likely the Reg/Rect unit that gets fried, and causes them to stop charging. There are diagnostic steps in the tech tips. There are several large white connectors BEHIND the fuse panel that the charging system plugs into, check and clean....folks have found them melted from corrosion and then resistance causing excessive heat! Clean the case to frame contacts of the REG/RECT as well, it grounds thru the case.
T.C.