Hey all.
Riding yesterday and the bikes tach just stopped and the bike lost power. This is electrical for sure. The bike will idle perfectly, but when I try to twist the throttle, it wont rev past 2 thousand and backfire. Periodically, the tach starts to work again, and all power is back, including reving fine. It wont stay though, the tach goes to zero and if wont run off idle.
Thoughts?

 

Regulator (do you have the stock unit?), battery, alternator. I'd verify them in that order, along with their connections to the system. Could be an intermittent 'open' elsewhere, too. But I'd check these first. Probably not much more than you'd have done, anyway.

Alan

 

I'd definitely do the mosfet R/R swap if it hasn't been done already. Look at the condition of the wires going into the r/r plug itself. A lot of times they will show signs for over heating. Use dielectric grease on connectors, check all ground connections etc.