Fellow 919 experts...
I've got an '03 919 - I believe I"m second owner, but not sure.
I purchased the 9er in April, and almost from the start, I noticed a small issue...
almost every ride, especially any sort of spirited ride, the bike with leak a little coolant out of the overflow, I'm talking only a teaspoon or so. the drops appear right beneath the overflow tube on the side opposite the kickstand. Additionally, once the bike has cooled, overnight I'd say, the upper rad hose appears imploded, like it wanted to suck coolant back into the system, but couldn't
Initially, I just figured the shop filled the expansion tank too full, so I sorta ignored it.
I check the expansion tank occasionally, and only once did I ever add water. close to 2 cups I'd guess, possibly less.
I've replaced the rad cap with a new one just in case it was caused by a faulty cap.
the bike doesn't appear to overheat unless I'm in town, in which case the fan comes on as expected.
so, any experts, mechanics, or whatnot, what would you suggest as the next steps to troubleshoot? keep in mind, I've only got about 3 weeks on the road up here... then i'll have to wait till the spring to heat up the coolant enough to leak again.