Slipping Clutch

[dbellemo692]

I just purchase a 2007 ST1300 ABS and within a few days the clutch began to slip in all gears. First ride it was cold and all seemed well. Once the bike got warm, maybe 25 minutes in. it would slip in all gears. I opened the master cylinder and the fluid was almost completely gone so I filled it. The next morning I took it for a test drive and it seems perfect until it got warm again and began to slip in all gears again. I also confirmed the motor oil level is good just in case and it is fine. If it needed to be blead I would think I would have the opposite issue because the clutch handle disengages the clutch I would think air would prevent it from completely disengaging. Am I correct? Any thoughts about what would be the cause? Thanks in advance.

 

[Larry Fine]

Welcome to the forum.

Yes, you're correct. Low fluid would only cause a failure to disengage the clutch.

The wrong oil type may have been used, or you need a new clutch pack (or both).

(Don't forget to soak the new fiber plates in the correct (non-energy-saving) oil type.)

 

[klaproth]

I agree with @Larry Fine, above- unless there are a ton of miles on the bike, at the last oil change, it was filled with energy conserving oil, and that has caused the slippage. Sometimes, just changing the oil will cure it. Make sure to bind the clutch lever back, to fully drain the clutch pack. Make sure the new oil is JASO MA rated.

 

[motornut]

Amen on the wrong oil, sometimes when someone is selling a motor vehicle it becomes a "Not My Problem Anymore". The low fluid in master cylinder sounds more like a fluid leak in the slave cylinder.

 

[Igofar]

If the master cylinder was low of brake fluid, it means your clutch slave cylinder leaked it out.
Look at the rear crankcase cover (back of engine) you’re probably going to see a yellow stain where it leaked out.
They are easily replaced, and if you do your own wrenching, will only set you back about $100 for all the parts you will need.
While it may/could be related to using the wrong oil, it’s more likely the slave cylinder failed.
Using the wrong oil could cause the clutch to slip, but would not explain where the clutch fluid went.

 

[dbellemo692]

You guys are all great, Thanks.
The bike has 68K on it so pretty low for an ST I think and it has always been in a garage so very clean and little corrosion.
I replace the fluid and have not lost more yet so we will see and I will look for the stain mentioned. Thanks.
I also want to have the whole bike gone through since it is old and Initials SG from this forum referred me on FB to a highly regarded mechanic at a shop in Concord NH that is great with Hondas and is an ST owner so I am bringing it there and it sounds like I will be in good hands. I think we will start with an oil change and a clutch bleed and see how it does. Hopefully not the slave or the clutch plates.
Love the bike.

 

[Al Gully]

Just a comment,
The 2nd ST1300 I bought 2 years ago had that symptom right after the previous owner had an oil change at out local honda dealership.
I seen the slipping comment on the invoice that he gave me when I purchased the bike.
Said right after he took it home from the dealer driving up a small grade, it started slipping.
Took it back to Honda and the comment said just ride it, no excessive throttle for a bit after the oil change.
No repairs were required.
Has the bike been sitting for a while, how old is the engine oil and what type of oil is currently in it.

 

[Igofar]

Running in oil would not make the clutch slip.
Not flushing the clutch fluid would, and them stating just ride it, may have just allowed the clutch fluid to move around after sitting a while and allow the dirty nasty clutch fluid in the slave cylinder to unstick from movement.
My money is still on a failing clutch slave cylinder.
After having so many people tell me their clutch works fine, and showing them how dirty and nasty the fluid is, and how good the system works when clean it surprises a lot of people.