VTR1000 - Clutch Slips when Hot: How to fix it

No matter what anyone else tells you the issue is caused by poor maintenance and age of the hydraulic system. This is simple and cheap to fix.

In the last two years I have seen this occur two times once in a Kawasaki ZRX110, a Honda VFR800.

The ZRX owner went as far as to install a complete clutch kit, put it back together with no joy…

Let’s look at this logically.

Your bike’s clutch slips, but only when the engine is hot. Hmmmmmm?

What happens when any fluid gets hot? It expands!

When brake fluid gets hot and expands it must have a clear return pathway back to the master cylinder's brake fluid reservoir. If it does not have a place to go, then it exerts pressure upon the only other path of expansion... The slave cylinder!

It pushes the slave out, the pushrod in, the clutch pack slightly disengages, you throttle up and bingo it's slipping.

To fix it: Pull the master down and clean clear all fluids return pathways fastidiously, Check for pitting in the bore and on the piston and install an OEM Honda rebuild kit using hydraulic grease for the kit seals.

Pull the slave cylinder. Check for pitting in the bore and on the piston, clean, and install a OEM Honda rebuild kit using hydraulic grease for the kit seals.

Install a braided clutch line, you will have better feel, plus OLD rubber lines have a nitrile inner pressure tube that can internally collapse when the clutch is released and also cause this issue by acting like a check valve, not allowing fluid to return, (this can also happen with brakes causing them to drag).

Pull the primary sprocket cover clean inside thoroughly. Once clean pull the clutch pushrod, clean and polish it note which end was at the slave cylinder. Coat with motor oil and reinsert as per the picture.

Reinstall with fresh OEM cover gasket. (Gasket prevents electrolysis and corrosion between the magnesium cover and the zinc plated steel safety ring spacer.

Fill with fresh DOT4 or DOT5.1 then bleed thoroughly go for a ride and report back.

In 99% of all, cases this is the fix.... this goes for any and all bikes with hydraulic clutches.

Also do not use automotive oil in your bike. Automotive oils have friction modifiers that are NOT wet clutch friendly. Although using them that will have less impact than the poor maintenance will. 

Have fun!