Joined May 2005
190 Posts | 145+
Sacramento California
Went for a nice long ride over the weekend. At the beginning, everything was nice and clean. Then I started to notice a mist of oil on the right side of the engine. It was VERY difficult to pinpoint the source of the leak. The entire right side seemed to have a coating of oil from the valve adjuster covers down to the bottom of the case and from forward of the stator cover to back just short of the sprocket. My right boot was covered in oil from the toe area all the way up to the shin.
I pulled the seat, tank (which also exhibits a bit of oil on the right side, especially around the right side petcock), and shrouds off and ran the engine with just the fuel in the float bowl in the hopes that the source of the oil would be apparent. No luck! I looked carefully at the crank case vent hose and it's dry with no evidence of seepage anywhere. I had just resealed the valve cover last week after replacing one of the rocker shaft caps and I paid particular attention to getting the head-to-cover seal just right (because it's leaked before in a spot on the left side). I made sure that the oil supply o-ring between the head and the cover was in place also. There are no bolts missing anywhere.
Throughout the approximately 60-mile ride, I monitored the oil level and it never appeared to drop so I imagine that the leak looks worse than it really is.
Later in the weekend, I was riding around in my running shoes and noted that the oil seemed to be spraying from the source based on the pattern of oil on my shoe so I began to wonder if the right side crank seal had failed and oil was making its way into the stator area. There it could be flung around by the flywheel and then blown out the hole where the stator wiring exits by the pressure pulses from the downward motion of the piston. In my mind, that does not explain the oil all the way up on the head and the underside of the fuel tank...unless...the oil was being forced up the stator wires. Hmm...
Has anyone had the right side crank main seal fail? What was the result?
I pulled the seat, tank (which also exhibits a bit of oil on the right side, especially around the right side petcock), and shrouds off and ran the engine with just the fuel in the float bowl in the hopes that the source of the oil would be apparent. No luck! I looked carefully at the crank case vent hose and it's dry with no evidence of seepage anywhere. I had just resealed the valve cover last week after replacing one of the rocker shaft caps and I paid particular attention to getting the head-to-cover seal just right (because it's leaked before in a spot on the left side). I made sure that the oil supply o-ring between the head and the cover was in place also. There are no bolts missing anywhere.
Throughout the approximately 60-mile ride, I monitored the oil level and it never appeared to drop so I imagine that the leak looks worse than it really is.
Later in the weekend, I was riding around in my running shoes and noted that the oil seemed to be spraying from the source based on the pattern of oil on my shoe so I began to wonder if the right side crank seal had failed and oil was making its way into the stator area. There it could be flung around by the flywheel and then blown out the hole where the stator wiring exits by the pressure pulses from the downward motion of the piston. In my mind, that does not explain the oil all the way up on the head and the underside of the fuel tank...unless...the oil was being forced up the stator wires. Hmm...
Has anyone had the right side crank main seal fail? What was the result?
