The center plug will have at least two wires in it-one power from the switch for the soleniod's coil and the other a ground. You can trace each back to where they come from or go to. To test you may have to cut into the insulation to probe. Pull the connector to see if it shows any heat damage or bad connection.

Understood- the center plug has power for the solenoid coil, from the ignition switch and the second is the solenoids ground.   Alright so I verified I have no voltage going to the starter positive when turning the IGN to START.  The ground of the starter has continuity to the common ground on the chassis.  The (M), Motor-side of the starter solenoid is getting no voltage when turning the IGN to START but the (B), Batter side is getting a clean 13.8 Volts and when tuning the IGN to start, doesn't drop below 12.8-12.6. 

So, the (M) side of the solenoid isn't getting voltage for some reason.  The service manual you sent, the electrical schematic is 'okay' for a general overview, but it looks like there are two or three AUX relays that play a role in this... Additionally I do not believe my model of 600 has the brake interlock. I pressed the brake just to make sure but since I've has this sxs, I've never had to press the brake. Transmission is in neutral as well, parking brake set.

I'll have to open up the dash and try to trace the ignition power that goes to the coil of the solenoid.  I did also confirm the ground of that middle plug (on the solenoid) has continuity to the common ground where the three wires are, below the CVT cooling elbow.

Puzzling...  Appreciate the assistance

The manual does have the wiring diagram and one with the starting system. The link to it is below and will expire in 48 hours so download it asap.

https://acrobat.adobe.com/id/urn:aaid:sc:VA6C2:7db32de4-73b2-433e-9191-ee9c198a5d4b

Hey really appreciate you sending over the schematic! That was very nice!  I downloaded it just now.  Also appreciate the sage advice.

Just to clarify; The (B) on the solenoid is the battery cable obviously, the (M) pole is motor (pretty sure right?)  and it's also a large gauge cable... that should be the positive going to the starter, correct? (see attached image) 

The center plug on the solenoid, that is the ground correct?? Which would be one of the three grounds (the large is obviously negative ground from the battery) correct?

If the IGN switch was having an issue, it wouldn't be sending current through to the solenoid to the starter then if the START side of the switch was bad correct? 

I'll definitely get on checking the voltage on the solenoid.

Hey everyone-  I have a 2013 cfmoto 600. 

Was running like a top with only 590 miles on it.  It just stopped wanting to start.  Turn the key and starter solenoid clicks clicks clicks.   Battery was on a tender.  Bought a brand-new battery.  Fully charged it outside the sxs.  Installed in sxs and same thing.  ignition to start, solenoid clicks away.   Jumped the battery off the truck, started right up.  Took new battery to auto store, checks fine. 

Used an external jumper box directly to battery, won't start.  Just clicks.  Removed new battery and used our camper trailers 12V battery... same thing.  Looked at fuses under steering wheel, all look good.  Contact cleaner just to make sure.  Removed solenoid and installed brand new one.  Doesn't start, just clicks.

Contact cleaner on the black/ middle wire leads (ground?) on solenoid (also on both positives, one from + on battery (B) and positive going to starter (M). There are three grounds when looking down with driver's seat removed, under elbows for cvt cooling shroud. One of these grounds goes to battery negative cable and I *think* one of the three goes to the middle socket of the starter solenoid.

No joy.

NOW when I jump the two poles on the solenoid with the ignition ON, it starts!  What am I missing here?  No schematics for this rig so trying to troubleshoot without.

***  The fuel pump does whirl when the IGN is on**

Would appreciate the help.

~Bryan