Do you happen to know what grade brake fluid is being used?

 

I assume OEM

 

Hmmmmm... Okay.

 

I was going to suggest flushing the entire thing and refreshing with DOT 5.1, but you can only do that if you are sure that system never had DOT 5 fluid in it.

I can't think of anything else to try at the moment unfortunately... 😕

 

The symptoms you describe is most probably a result of air in the system. The solution is bleed the air from the system that you did. After bleeding the system the clutch should again feel normal, but if the problem progressively returns then you need to find the source of the air leak.

If the clutch feels normal when the bike is warming up, but develops this problem only when the bike is hot, then there's water in the system that boils (producing compressible water vapor) from the engine heat and mimics air in the system. The solution is to replace the clutch fluid on a 18 month schedule from a sealed container. Hydraulic clutch and brake fluid absorb moisture from the air directly.

If the problem also occurs when cold, then an air leak from the master cylinder, slave cylinder or beed bolts is the likely cause.