Alternator?

[Christmas]

My 2009 G650GS won't start. 12k miles on it, oil change done in April 2015.

Tried to jump it -- it'll turn on, and engine will start, but once I disconnect the cables, the engine dies immediately. I should check the connections to the new battery I just put in a month or two ago, but from reading the forums, I'm guessing it's the alternator.

My question is, how much is this kind of repair going to cost, and where should I take the bike?
Thanks for the help.

Anastasia

[kioolt]

Some bikes don't charge at idle. That could explain why yours dies when you remove the jumper cables. I would at least try charging the battery overnight and then putting a voltmeter on it to see how it did. Alternately, before taking the jumper cables off of the bike try increasing the rpm just a little.

[JimVonBaden]

Very good chance you have a bad cell in your battery. Sitting will sometimes cause the cells to short out. Replace the battery first. I have a spare if you want to borrow it.

Jim

[Christmas]

Turns out that when I put the new battery in, the cables were not completely tight. I took the panels off, and as I leaned on them, I could hear the clock whirring back to life. Explains why my tachometer was going crazy on recent rides too, zooming from 4kRPM to 8K (pegged!) RPM. I guess I was losing power as I hit bumps in the road, then GAINING IT BACK quick enough to freak the thing out.
Anyway, crisis averted. Stand down.
Thanks for the advice, friends!