83 900RK Not Cranking

So after a while of sitting (2 seasons) due to tank pinhole issues which have been remedied by sending them off to Moyer's Tank Renu in Greensborough, PN...
The bike was running great when I put her away (about 2 years ago), and now after getting the tanks back and getting the carbs synced and cleaned (and even after a couple hundred miles of no-issue-blast-me-around-the-back-roads-fun) I have a no start issue.

She was taking me to work and she lost power mid-trip. Felt like she would fire every once-in-a-while, but was not running by much. When I pulled her over, she was a no-start/no-crank.

Current situation...
I've been through the diode pack and the side-stand relay (both good per this forum and the Hayne's manual), resting battery check (12.4V after the quitting on me at 80mph), and a reg/rec charging check of 14+Vdc at 2200RPM a few days ago.
In Neutral, ignition key to 'ON', Run Switch to 'ON', headlight and accessory (instrument panel) lights come on...
Depress starter switch, headlight turns off, dash lights turn off, oil light comes on, starter relay solenoid clicks...
and nothing... No starter motor crank, no engine turn, nothing...

Besides chasing voltage from the starter relay solenoid to the starter motor, anything obvious I'm missing?

 

Voltage from relay to starter motor after starter switch is pushed. Pulled starter motor and applied external 12V source and the thing spun up just fine, so I'm really confused as to why the bike isn't cranking.
As a side note, the voltage on the resting battery has been dropping 12.6 on Monday, 12.2 Tuesday and 11.8 when I finally got her out of the back of the truck today. Might I have something that is slowly leaking to ground?

 

It is possible to have a slow/slight parasitic drain but I think I would lend more towards the battery going south. You can do an amperage test to determine if there is any draw. Also I would test the voltage on the input wires to the solenoid, disassemble and clean the starter button contacts/check for any possible pinched wires in that circuit, etc. See what you find there

 

Battery voltage has to be above 12v when cranking in order to have enough juice to provide spark. Any lower, and it will spin, but not fire up.

 

So is it your ignition switch contacts that are pooched?

 

Check the battery voltage when the start button is depressed and the solenoid is closing, it needs to maintain at least 10 volts at the battery, If OK,

Repeat test measuring at the main fuse and engine chassis to verify low and high side connections. If OK,

Repeat test one more time measuring at one of the other 3 fuses to verify ignition switch.

If OK, then:

Put the bike in neutral and on the center stand. Use an old screwdriver and short across the two large terminals on the starter solenoid, the starter should spin and the bike should start if the key is in the "ON" position.... Side stand up in your case to run unless you have fixed the no spark in neutral from your previous post.

If OK and you can hear the solenoid clicking but no starter engagement the solenoid is likely defective. You can test the solenoid by removing the small connector and applying 12V across the terminals. The solenoid should engage and the starter should spin.

 

So I got another while to play with her tonight and I have found that...

1.) Battery is at 12.4V after trickle charge for the night (brand new Yuasa bought this season)

2.) All fuses show continuity.
When the bike is on the main fuse shows 12.4 volts from lead (and far side) to chassis. The rest show about 11.5 from lead to chassis. I don't know if this means something important or not.

3.) Starter relay and connection to starter motor.
The wire from the starter relay to the starter motor shows continuity.
When the bike is "on" (key on, run switch on), voltage across the two starter relay pins reliably jumps from 0 to 12+Vdc when the start switch is pressed.
Aside from showing continuity, the pin on the starter motor also shows 12+Vdc when the starter switch is depressed.
And still no cranky-cranky of the starter motor.

4.) And then to the catch all starter relay jump with a screw driver trick... Still nothing.

So I pull the starter motor again after all of this and it does spin with 12V 10amp applied (but only sometimes) and she did spin when I hooked it back up to the battery and grounded it out on the foot rest (but only sometimes), so I'm going to crack the starter motor and check the brushes, but not tonight.

I'm not sure this explains why she died when I was rolling down the highway though. Another problem for another day.

 

Good place to start, get it cranking. Here is a nice link on rebuilding the starter:

http://www.xj4ever.com/starter brush replacement.pdf

Yea, the starter is not going to explain that. What is the condition of the fuse box? Are you running stock or has it been upgraded to blade fuses?

Any other info on the ignition system, checked spark plug caps, coils, pickups for proper resistance. Cleaned / inspected connectors for corrosion?

 

Well, we have a miracle on our hands. I pulled the starter motor off last night and cleaned it up this afternoon. Brushes are a little low, but they are making contact and spinning the starter motor. Removed lots of carbon are greased the planetary gears, polished the copper cummutator, etc. Slapped it back on the bike, polished the terminals at the starter relay and the starter motor and BAM!!! She lit up like a torch. Two cranks and she was running strong. I'll run through the charging system checks and then it's road test time. Any one in Ohio and wanna get out this weekend?

I also was able to find the bad diode in the diode block and dig though my pile of electrical odds and ends and find another diode pack that tested OK. She will also now run with the side-stand down while in neutral.
She works, and will need brushes in the near-ish future, but that is a project for winter parts wishlists.

Thanks for the help and encouragement. I actually know how to do voltage-drop tests now. And how not to shock myself when testing starting motors while off the bike.

 

I ass-u-me the 900 has a similar starter as the 650. Brushes being "low" is ok as long as you can still see the 'minimum wear' mark.