MY 2016 959 I bought it this year with 2200miles. In preparation for track use I have thoroughly inspected everything and and prepped it. Occasionally after it has been sitting for a week or so it drops a little coolant. When it is on the kickstand it appears on the left side as if it is coming out of the bleed hole. I have read every thread written in English about this issue.
Two weeks ago I was looking things over trying to figure out why. I found my reservoir was about 8oz overfilled and was surprised I could make such a stupid mistake and shrugged it off thinking I overfilled it due to the difficulty to read the reservoir level with the light colored Engine Ice. Now the bike has been on my lift for two weeks and it spewed out another small amount of coolant. This time the bike is straight up and down and the coolant ran down the right side of the motor and pooled a tiny bit on the left by the shock mount.
Back in I go looking. What I found was it was leaking at the junction of coolant line to the Vertical cylinder. Just a tiny amount that was pooling up and running down. If the bike was on its kickstand it runs right down to the weep hole and you could think that was the issue because you would see a little pool running out from there, why would look any further up the engine?
When I released the suspect clamp I got a substantial pressure equalization I was surprised because the bike had not been run for two weeks. Originally I thought it was under pressure and I cannot really explain that but if it was actually pulling a vacuum and I can make sense of it. I believe it is pulling air at that point which is the highest point in the coolant system. When the bike gets hot it pushes a little coolant into the reservoir then cools down to pulls air in from the leak. More air in the system the more it heats and expands. Best I can figure I have got a poor clamp install and or a bad radiator cap. Oh yea, my radiator was about 8oz low, so it is pushing coolant out without drawing back in. Parts are ordered. The leaking junction is visible if you remove the right side fairing and the coil pack in case someone else has these symptoms. Photos below
Thoughts?
t_bare
Two weeks ago I was looking things over trying to figure out why. I found my reservoir was about 8oz overfilled and was surprised I could make such a stupid mistake and shrugged it off thinking I overfilled it due to the difficulty to read the reservoir level with the light colored Engine Ice. Now the bike has been on my lift for two weeks and it spewed out another small amount of coolant. This time the bike is straight up and down and the coolant ran down the right side of the motor and pooled a tiny bit on the left by the shock mount.
Back in I go looking. What I found was it was leaking at the junction of coolant line to the Vertical cylinder. Just a tiny amount that was pooling up and running down. If the bike was on its kickstand it runs right down to the weep hole and you could think that was the issue because you would see a little pool running out from there, why would look any further up the engine?
When I released the suspect clamp I got a substantial pressure equalization I was surprised because the bike had not been run for two weeks. Originally I thought it was under pressure and I cannot really explain that but if it was actually pulling a vacuum and I can make sense of it. I believe it is pulling air at that point which is the highest point in the coolant system. When the bike gets hot it pushes a little coolant into the reservoir then cools down to pulls air in from the leak. More air in the system the more it heats and expands. Best I can figure I have got a poor clamp install and or a bad radiator cap. Oh yea, my radiator was about 8oz low, so it is pushing coolant out without drawing back in. Parts are ordered. The leaking junction is visible if you remove the right side fairing and the coil pack in case someone else has these symptoms. Photos below
Thoughts?
t_bare
