Hi all, and happy new year!
My bike sat for about two weeks in 30 to 50 degrees weather in my garage. When I first started it in neutral this morning to go to work, everything was fine until I put it in first. I pulled the clutch all the way in, it felt much softer than usual. When I kicked it in first, the bike launched forward and stalled. Clutch pulled all the way in...

I tried a few more times and realized there was still some clutch disingagement, only when the lever was pulled all the way to the handle bar, but even so the bike would still move forward in 1st.

I then remember some thread that was posted possibily by Brian (before the forunami) in which he and others described something similar, where the clutch engagement point would be change to almost all the way pulled in when the bike was cold, and then go back to normal later.

I took a chance and drove the bike as it was to work, and 10 miles in or so it came back to normal. The bike then sat then for 4 hours in 45 degrees. I drove it home for lunch and it was normal, no issues.

I remember Brian had his dealer diagnose the issue under warranty, and it turned out to be the master cylinder. Does this sound like the same issue? What could cause it? Any ideas? Should I just shrug it off since it's fine now?

It was the slave not the master as I recall.  My buddy had a similar issue and we replaced the slave seals and all was well after that.  BDF has a photo of his slave showing the wear which necessitated the replacement.  For my friends, there was no noticeable wear and replacing the seals was the answer for his bike.  You could try bleeding first.  If that doesn't work maybe look at your slave and see if some work there is needed.

For what it's worth, my KLR will do the same thing if it has sat for a few days.  I start in neutral, gear up and pull in the clutch, I have come to expect the brief jerk, once I have ridden it for a bit it is back to normal.  I'm thinking it is the clutch plates get dry from sitting and they simply dont disengage when the clutch is pulled in.

I would recomend tearing the engine apart, rinsing thourogly with your favorite bourbon (your throat), reassemble, tear apart again because you left out that thingamajig, rinse your throat again, call Brian, put it all back together again, start it up, find out you have 6 reverse gears and no forward, plead with your wife that you will never again practice shade tree mechanics on a bike again, and go buy a slow 2012 C14   Problem solved.

Happy New Year

Happy New Year back at ya' Haroldo. Good to see you posting....

My problem was air in the system caused by a worn slave cylinder. The cylinder assembly was replaced under warranty and after a few sessions of bleeding the clutch again operated normally. A new seal <may> have fixed the problem but a new assembly was not much more money and my dealer thought it was a lot more likely that the new assembly would cure the problem instead of replacing single components until the problem went away.

This is what my clutch slave cylinder looked like:


Brian

Hi all, and happy new year!
My bike sat for about two weeks in 30 to 50 degrees weather in my garage. When I first started it in neutral this morning to go to work, everything was fine until I put it in first. I pulled the clutch all the way in, it felt much softer than usual. When I kicked it in first, the bike launched forward and stalled. Clutch pulled all the way in...

I tried a few more times and realized there was still some clutch disingagement, only when the lever was pulled all the way to the handle bar, but even so the bike would still move forward in 1st.

I then remember some thread that was posted possibily by Brian (before the forunami) in which he and others described something similar, where the clutch engagement point would be change to almost all the way pulled in when the bike was cold, and then go back to normal later.

I took a chance and drove the bike as it was to work, and 10 miles in or so it came back to normal. The bike then sat then for 4 hours in 45 degrees. I drove it home for lunch and it was normal, no issues.

I remember Brian had his dealer diagnose the issue under warranty, and it turned out to be the master cylinder. Does this sound like the same issue? What could cause it? Any ideas? Should I just shrug it off since it's fine now?

Thanks for the replies.

Brian

  I rode it again this morning after sitting all night, and no problem at all. If it were air in the system due to a worn slave, wouldn't I be noticing it more often?

  It will be hard to fix this if it doesn't happen anymore. I like the idea that it might be the clutch plates getting dry, but that wouldn't explain the clutch lever temporarily feeling much softer and looser than usual.

Probably unrelated but my friends '06 1600 Vulcan does the same thing. It also clears up.

Awe, come on, we really need another epic thread

Yes, it would seem to be the way you describe, and further, it doesn't make any sense that a hydraulic system would 'recover' when used and then fail, at least partially, just because it was left sitting. But that is exactly what I found mine doing on several occasions and the eventual (and hard found) cure was thorough bleeding- maybe even excessive bleeding. After that the system acted fine and consistently again. ?? I could not tell if there were small air bubbles bleeding from the system because the bleeders themselves leak air so there is a steady stream of small bubbles in the line even when bleeding a system with no air in it. I tried all the known 'tricks' to seal the bleeders (Teflon tape, packing the threads with grease) but found those methods really do not work.

A better way to bleed the system (any hydraulic system) would be to power bleed it from the bottom up. Pressurized fluid introduced to each bleeder would force any air in the system 'up' into the reservoir; it works better because that is the natural direction air bubbles tend to move anyway. The two problems with doing it that way are that the bleeders leak around the threads and brake fluid creeps everywhere on the caliper or slave cylinder, and the master cylinder reservoir has to be emptied. Also you have to be careful not to get a shot of air bubbling up through the reservoir when starting as it tends to get brake fluid all over the bike.

Brian

Thanks for the replies.

Brian

  I rode it again this morning after sitting all night, and no problem at all. If it were air in the system due to a worn slave, wouldn't I be noticing it more often?

  It will be hard to fix this if it doesn't happen anymore. I like the idea that it might be the clutch plates getting dry, but that wouldn't explain the clutch lever temporarily feeling much softer and looser than usual.

Haroldo,

My C14 did the exact same thing that yours did early this year after sitting in the cold garage for a couple weeks. I noticed it before I took off and just pumped up the clutch a bit and all was fine. The issue never came back. I've bled the system since then and it seems that there might have been some air in there.

Awe, come on, we really need another epic thread

I'm new, so I will bite.

I always bleed the brakes on my airplanes from the bottom up. Not sure when car people and airplane people took different paths. Of course, aircraft use a much different fluid also.

My experience with racing cars showed me that bubbles can be caused by excessive fluid speed/cavitation when bleeding. A pressurized bleeder can often solve this problem, but the pressure only needs to be very low to move the fluid.

How's that for a start? I hope these are new responses.

There are really two issues - master/slave cylinder leakage on hydraulic clutches, but all wet clutch bikes have a slight fluid friction drag when the clutch is disengaged, which is worsened by cold, congealed oil.

As an aside, my BMW 1200RT, which has a dry clutch, had an annoying characteristic that often times it wouldn't shift into first from neutral at idle, requiring a slight clutch engagement to effect the shift.  Never had that issue with any other motorcycle I've owned.