Join Date: Mar 2013
Location: In the twisties around Hendersonville, NC
There were a number of similar oil leaks a few years back but I have not seen any recent posts.
The most common source is what you suspect, the #9 o-ring that seals the pump assembly to the engine case. Easy fix.
Less common is the actual oil seal in the pump itself. As you saw in the parts diagram, there are two seals, an oil seal and an water seal. There is a weep hole in the housing between these so it is impossible for any leak to contaminate the other system. You will see the weep hole easily when you pull the pump out.
Change the o-ring first and see if it fixes it. It is quick and cheap.
Do be careful that the water pump drive shaft slot is aligned with the oil pump drive shaft tang in the engine. The pump should slide in all the way with little pressure. Some have damaged the oil pump by not paying attention to this.
Post an intro, with pics of your bike, in the "new riders and members" section when you get a chance.
"Riding well is difficult, riding poorly is easy and painful."
If you think reading is tricky, how the hell are you going to follow troubleshooting directions?
- Nick Ienatsch
"We're all here because we're not all there" - Guy Favron on Gold Rush