Motorcycle Repair: Starting problem, motor carbon brushes, trouble shooting guide

Question
Hi Mark Thanks for the time! Here is the problem. I have a 85 Yamaha XJ700 Maxim, Everything was fine,went for a ride came home for a bit then went to go back out, pushed the starter button and nothing. When I turn the key on I hear a click, this is normal but when I hit the start button there is no click, nothing. The headlight goes out and the oil light comes on, again normal.The kill switch is on, side stand up and in nutral. If I cross the posts on the starter relay the bike will start(also starts with a push). The relay is new used and I'm pretty sure it works. The starter was replaced a year ago. The start button has been a little sticky for a while.Is there a step by step trouble shooting guide you can help me with? I sure would appreciate any help with this matter.
The Battery also has a good charge(New Battery at the start of the summer.) I do have a wiring diagram in the back of the owners manual if this helps. Thanks again. Also any info no bypassing side stand switch.

Answer
Hi Jeff,

The first click is likely the fuel pump working normally.

The usual cause for the problem you're experiencing is:

Weak or defective battery
Worn starter motor bruses
Worn or defective solenoid
Worn or defective starter motor
Worn or defective starter motor clutch
Corroded or defective starter button

The battery may have been purchased this summer, but may be undercharged or defective. Only way to know is by voltage check and specific gravity check of each cell.

Starter motor carbon brushes wear with time and need to be replaced. Measure length of brushes and compare with service manual service limits. Brushes are about 3/4" long when new.

Solenoid is an electro magnet and should click with 12VDC applied to the primary winding. The secondary contacts sometimes become corroded, welded or pitted from current arcing.

The starter button contacts may become corroded due to exposure to the elements of weather and washing. I've found non-conductors between the button contatcs in the form of spiders, spider webs, and dead insects (believe it or not).

I'll have to send you information of how to test and repair these and the other possible causes. Send me an email address as requested. I'll return the related tech files.

Respectfully,
Mark Shively