Hey guys. My 06 is having a minor clutch slippage issue. It started about 3 weeks ago and has been a constant annoyance. My bike has just over 8k miles on it so I can't imagine the clutch would need to be replaced (despite what the wretched awful mechanic said). Happens in 3rd and 4th gear, sometimes in 2nd, rarely/never in any other gear. Usually around 5k or 6k rpm. It will jump to 8k rpm and hold for about 2-3 seconds before dropping down and catching gear.

It primarily happens when it's cold. I start my bike in the morning with a little choke. Choke off after about a minute. Let her warm up for about 5-7 minutes before riding to work. I take it easy for the first 10 minutes or so and even after all that warm up, she will slip once I get to 3rd gear. Afternoons aren't bad. Usually after 5 minutes of riding, no or very little slippage. Did a long ride this weekend and had absolutely no issues after 20 minutes. Temps here are 50°F in the morning and 75°+ in the afternoons.

What I've done to try to fix it:
Clutch adjustment (all 3 points) - lock nut on the lever was loose, tightened and only a little better. Played with all 3 adjustments and only minor improvement
Oil change - complete change including filter. Using recommended weight, motorcycle specific (Valvoline), no additives (not synthetic though) - no change
Tightened chain - was very loose, - no change (but rides smoother)
Carbs were cleaned 6 months ago along with valve check.
Cleaned front sprocket - no change

I have new plugs on the way though I highly doubt that will help. Anything else I can check before looking at the clutch plates? She usually doesn't like the cold, but this is a new reaction to it.

Sounds like #6 is tight (No Freeplay) and holding the clutch open.
If #6 has freeplay and it still slips..it's the oil, no way is the clutch already worn out

Do what Stevo said. He suggested it to me a month or so back and it helped tremendously.

It will take some fiddling to get exactly right, it did for me at least. Follow the intructions in that picture, and if you still find it slipping, loosen it a 1/8 of a turn at a time until it clears up.

I will go with that too 

Needs a touch more slack in there, get on it ASAP, the longer you leave it the more chance of doing some permanent damage to the plates.

Thanks guys. I'll play with it a little more. I followed the manual and backed the screw out a couple turns, retightened, then out half a turn. Didn't help much. Lock nut might have tightened it up though. When I was adjusting it last night, I noticed that my lock nut won't come off now. It's catching on the threads and any movement of the lock nut moves the screw. I'll try adding more play and see if I can get that lock nut sorted.

What exactly is your symptom, revs shooting up while riding with constant throttle?

Quote from: bmf on March 31, 2015, 09:23:28 AM
What exactly is your symptom, revs shooting up while riding with constant throttle?

Increasing speed, more throttle, revs shoot up but bike doesn't increase speed according to revs. Revs eventually drop and bike begins to speed up.

For example, pull away from a stop light at regular acceleration and shifting. A car pulls out into my lane up the road and I want to get in front of the car in the lane next to me. 4th gear 6k rpm at constant throttle; twist the wrist quickly to pass, rpm jumps to 8k rpm but bike remains at constant speed for 2 seconds. Rpm drops back to 6k and bike begins to accelerate and rise in rpm. Can't imagine that would be anything outside of the clutch slipping.

Correct pushrod freeplay is important to proper clutch action. You need to be able to hold the nut while you adjust the screw and then hold the screw while you tighten the nut.  I clamp vice grips on a 10 mm deep wall 3/8 drive socket and reach thru the socket with a screwdriver to make that adjustment. 

...lads... if the previous owner stuffed up and used friction additive type oil in it.... even with the proper oil now, would any residual old oil on the clutch pack cause continuing issues? Or would it flush out?

It would flush out.
Semi-Synthetic oil is just dino oil with synthetic.
It's the synthetic part that causes the clutch slip.
With an oil change you reduce the percentage of synthetic oil in the engine; however, it's entirely possible that the clutch already got worn out because of the slip, and better oil won't work.

And actually temperature has little to do with clutch slip. If anything, the hotter it is the more chance on clutch slip.
It looks more like a clutch cable issue (tensioned too hard); with the cold, the cable shrinks, and pulls the clutch open slightly, reducing friction.

And thirdly, if it was the oil; unless the clutch was totally worn out, it would usually only happen in 5th or 6th gear. not in 2nd.
Because there's less resistance in those gears, and the clutch will be rotating faster.
Clutch slip happens more often in slower rotating clutches (aka 5th or 6th gear) than in 1st, 2nd or 3rd gear.

Aside from the forces applied on the clutch, I also believe it bathes in less oil when rotating fast (centrifugal ejects oil from the centers).

I'd put my 2ct on the clutch cable.

I think most of what you said is fine, MeeLee; however, I just want to point out that synthetic in and of itself isn't the cause for clutch slippage. I use full synthetic and have zero issues. Problems come with oil when you have "energy-conserving" oil or friction reducing oil.

Quote from: MeeLee on March 31, 2015, 07:49:52 PM
It would flush out.
Semi-Synthetic oil is just dino oil with synthetic.
It's the synthetic part that causes the clutch slip.
With an oil change you reduce the percentage of synthetic oil in the engine; however, it's entirely possible that the clutch already got worn out because of the slip, and better oil won't work.

And actually temperature has little to do with clutch slip. If anything, the hotter it is the more chance on clutch slip.
It looks more like a clutch cable issue (tensioned too hard); with the cold, the cable shrinks, and pulls the clutch open slightly, reducing friction.

And thirdly, if it was the oil; unless the clutch was totally worn out, it would usually only happen in 5th or 6th gear. not in 2nd.



Because there's less resistance in those gears, and the clutch will be rotating faster.
Clutch slip happens more often in slower rotating clutches (aka 5th or 6th gear) than in 1st, 2nd or 3rd gear.

Aside from the forces applied on the clutch, I also believe it bathes in less oil when rotating fast (centrifugal ejects oil from the centers).

I'd put my 2ct on the clutch cable.

WARNING!!!

There are more holes in this post than a welders t-shirt!!

Nah... than a acre of lace curtain!

 

There are several points in the post I would like to open up for debate but lets start with this one........

Because there's less resistance in those gears, and the clutch will be rotating faster.

I say engine rpm governs clutch speed and it has nothing to do with road speed and gear selection. Lets ask ourselves........How fast is the clutch tuning at 3000rpm in 3rd and how fast is the clutch turning at 3000rpm in 6th?

Discuss 

I know this!.... it's like when my MSF instructor a few years back asked... 'and at 60km/h how long will it take to travel 3 seconds?' ... yes... how LONG ..

It might be a brain/clutch/mouth moment?

Love when a simple "fix-it" thread turns into a "how does it work" thread

Clutch issue has been fixed. Tested it yesterday and this morning (which was significantly colder than usual). Despite turning the adjusting screw out previously, the lock nut was catching the threads and tightening the screw with it. This time, I pulled the screw out plenty and made sure to hold it in place while tightening the lock nut. Clutch now disengages at about 10-20% release (which is really low) and engages at about 40-50%... so I have a lot of travel before I get any pressure. Stalled it the first time since I wasn't used to such a quick clutch, but got used to it pretty quick.

No more slipping, runs much smoother, and feels healthy again. I'll probably adjust the play at the lever to get the amount of slack I want.

Thanks for all the help!

Sweet! Good news.

Since we're talking about clutches, is there a way to modify when it engages along the lever pull?

I'd like to tune that a bit, but I haven't been able to figure it out.

Quote from: sledge on April 01, 2015, 01:26:02 AMHow fast is the clutch tuning at 3000rpm in 3rd and how fast is the clutch turning at 3000rpm in 6th?

Discuss 

Because the clutch basket is connected to the primary drive the answer is the same Rpm...do I win? 

Quote from: Iarn on April 01, 2015, 07:43:46 AM
Sweet! Good news.

Since we're talking about clutches, is there a way to modify when it engages along the lever pull?

I'd like to tune that a bit, but I haven't been able to figure it out.

#6 has to be set right (freeplay), all tweaking has to be done with cable length