Join Date: Apr 2010
Location: Manchester, NY
Year/Make/Model: 2017 Vaquero ABS
Displacement/CC's: 1700 cc
Color: Candy Cardinal Red
I had to change out the stator on my 07 900 Custom at about 21k miles. When I first started looking to find the charging problem I also found what appeared to be oil in that plug. I don't really know what it was or where it came from but after replacing the reg/rec I have always used dielectric grease to lube the contacts and seal the plug. 30k miles later I haven't had a charging problem or 'oil' in the plug.
You should do some charging system checks though. Check the AC output of the generator and the DC voltage across the battery terminals while running (at a minimum). This will give you an idea as to whether or not your system is trying to charge the battery or whether you need to do more testing. To check the AC output properly, you'll need a tach along with your voltmeter.
Also, once you get the problem worked out, consider installing a battery gauge. I put a Kuryakyn on mine. Depending on how you wire it up it can monitor your system voltage or charging voltage. It won't tell you everything about your electrical system. I refer to it as my peace of mind gauge.
Last edited by SteveJB; 07-11-2019 at 02:47 PM.
Reason: Added battery gauge note.