Clutch slip when it hits 6000rpm or wheel spin?

[jwb125]

Hi, im new to the vamx and am either getting clutch slip when I hit about 6000rpm or the tyre is spinning up? Anyone have the same issues? I can have the bike in 5th doing 25mph and roll on the throttle and no clutch slip? Its happened a few times now but only when I really nail the trottle when its warm? Any ideas? Thanks in advance. Jase

 

[MaxMidnight]

Welcome to the site. :clapping:

How many miles has the bike done; what gears do you get this in?
Is it every time you hit 6K?
Has it had a car oil with a friction modifier in it? If you aren't sure then it would be worthwhile changing it as a matter of course.

Bleeding the clutch is unlikely to help but if it hasn't been done for several years won't do any harm.

If it is a high mileage bike or has had regular hard launches then I would first inspect the clutch discs and diaphragm spring.

Thickness of the friction plates is between 3.1 and 2.9mm, minimum is 2.8mm but I would replace them before it gets that low. Check the steels for flatness and signs of bluing.
The diaphragm standard height is 7.0mm with a lower limit of 6.5mm.

Whilst you have the plates out also check the clutch basket for any notching which will impair smooth engagement.

If you want to get a little more 'grab' then the half plate can be swapped for a full plate. You will loose the damping washer as well which will result in slightly less smooth gear engagement and a bit of noise but (IMHO) this isn't really noticeable after a few rides.

Should that not sort the issue then check that the lever isn't binding and that the fluid return hole in the M/C is clear. Check the slave for a build up of corrosion or crud which may stop it returning fully.

If not dome so already then also have a look at V Max Chat, where you will also find a lot of helpful folk.

 

[jwb125]

Thanks Steve, its a 1989 with 32000 miles, it came with no history and Im waiting for oil filter etc to come so I can service it. Only noticed it in the lower gears upto yet as I havent had it flat out but it seems to rev high when it hits 6000 if you nail the throttle just before, if you roll it on no problem

 

[MaxMidnight]

At that sort of mileage then I would think clutch plates are the most probable.
Mine showed similar symptoms at around that distance.

Seemed to be more noticeable before the motor had fully warmed up. The friction plates were still within the wear limits but new ones sorted the issue. Also replaced the half plate at the same time.

Service schedule here.

 

[eggohead]

I would say replace the clutch. When you do put in a full plate on the inside not the half plate. Mine started slipping this year and now it's good.

 

[jwb125]

Cheers gents. Will give it a bash

 

[dannymax]

My 1260 does the same thing.....it's the clutch. This winter I'll replace the friction discs & bead blast the steels, pretty sure that's what yours needs too.

 

[maleko89]

You can test for clutch slip. Shift to 5th gear and bump front wheel against solid structure. Rev to 4-5K and dump clutch. It'll either stall or keep running (slip).

 

[MaxMidnight]

My 1260 does the same thing.....it's the clutch. This winter I'll replace the friction discs & bead blast the steels, pretty sure that's what yours needs too.

Perhaps Santa will bring you a Lock-up Clurtch?

 

[jwb125]

Would you sudgest going down the barrett upgrade route or just normal for just road use. Dont plan on taking it down the strip but it will get USED LOL. Also ive seen orient express do the plates, do you know if they are just replacements or are they for a lock up?

 

[MaxMidnight]

Would you sudgest going down the barrett upgrade route or just normal for just road use. Dont plan on taking it down the strip but it will get USED LOL. Also ive seen orient express do the plates, do you know if they are just replacements or are they for a lock up?

Given that you will (probably) replace the pates I would run with that first.

If all is well then the money saved could be invested in other 'safety' related items! :biglaugh:

 

[eggohead]

I cann't say which clutch Mod is best. I didn't know I had a Barnett until I pulled the cover off. I was going to do the double D Mod. There is a lot of info if you look it up on this site. I did take mine to the track last week. I am still not used to the way it grabs since changing out the half plate for a full one. I noticed it grabs a little harder...

 

[DMAN999]

For normal road use I'd go with either the Barnett or the stronger PCW clutch spring.
I have a Barnett and I replaced the 1/2 friction with a Full friction and I'm very happy with it.
I will say that the with the 1/2 plate still in it did seem to shift a bit smoother though.
As for Friction plates, stick with Yamaha OEM.

 

[jwb125]

Thanks gents

 

[rebeltaz83]

i have a 97 with 15,000 miles. i was running valvoline 5w 20 motorcycle oil and noticed my clutches were sliping. in all gears, it would rev high, but it wouldn't go. so i changed the oil and filter, got it good and hot, drained the oil, and put in shell rotella heavy duty diesel oil, and no more slipping, for now. but i did do a clutch cover gasket, and a segment and noticed the clutches should be changed. i think i'm gonna go with pcw seems they supply everything. nd they are only about 3 hours from where i live.

 

[Fire-medic]

I used the PCW extra friction disc & their extra-duty diaphragm spring. It comes w/a gasket. All I did was use some wet or dry sandpaper to roughen the steelies & reassemble. It worked great. You get a positive lock up and that surge when the clutch re-engages after a high-rpm shift is great. Stick w/the stock friction discs. The replacement friction discs, the spring & gasket was ~$160 shipped.