When removing the thermostat and cover to install the ThermoBob, it was much easier to see the outside of this passageway. I put compressed air gun against the outside hole and tried to plug the plug-well hole with my finger to see there was any leakage. I couldn't find any. I still get a very occasional drip out the hole and credit it to a slight porous point that allows the coolant to escape. While it used to leak after every ride (a drop or three), now its so rare I don't remember the last time it happened.

So to Miloarrow's post: is your plug getting fouled? After looking closely at this, I don't see how a pourous-casting leak, like I believe I have, would allow coolant into your cylinder to foul the plug. My bike has pretty much ran well and this leak didn't cause and poor performance that I've identified.

 

MILOARROW your bike has more than one issue and that is why it is hard to diagnose. Electrical as in you speedo reset, and then and issue with a leak that could be from a porous casting and I dought it's fouling your plug, I'll bet that will be traced to your electrical issue.

 

Scott, did you ever figure out what caused the slight drip of coolant? I noticed the same thing recently. Thanks!

 

Me too... just s drop now and again... I haven't really worried about it enough to spend any energy finding it, but enquiring minds want to know.

 

Holy thread revival, Batman!

The best I can tell is that the head casting is a little porous. The other thing is that coolant could be dripping into the spark plug well from a radiator or hose, but in all my examination I found no evidence of this. Mine has not dripped in a long time.

 

Thanks Scott!