Motorcycle Repair: Slow cranking, yamaha fj1200, starter solenoid

Question
Hi Falcon,
Yamaha FJ1200 1989

The bike has been sitting in the garage over winter with a start up every 3/4 weeks. The battery is about 6 months old & has been kept charged up on a regular basis.
My prob is that when I went to try starting it the other day it cranked over at about half the normal rpm as if the battery was a bit flat,I dissconected it & put jumper leads from the car to the terminals but this made no difference. I took some readings which were---batt voltage whilst cranking, 11.9v, voltage at terminal on s/motor whilst cranking about 6v. I took the s/motor out & had a look inside, the brushes are good as is the contact area they run on, not sure where to go from here. your opinion would be greatly appreciated,  Chris..

Answer
Hi Chris.
 You could have a battery that has a bad cel.  You need a hygrometer for that, to check the battery fluid state.  You could also have a short in the starter motor circuit, but my money is on the battery.

1)  Get a battery hygrometer for motorcycles and check the battery's cels.  All of them.

2)  check the starter circuit and starter solenoid for bad components and wiring.

Good luck.
FALCON