4th gen clutch issues

I looked but I didn't see if wgregt said if he checked the clutch fluid.

When I installed my steel Braided Clutch line and I was draining the fluid from the Master everything looked good. Fluid in the sightglass was clean looking and looking down into the Master showed nothing out of the ordinary.

It wasn't until I was draining the fluid and I suddenly couldn't get it all to pump out that I noticed a layer of brown mud/sludge on the bottom of the Master.

 

!st gear WOT acceleration is the quickest, and subsequently it has the highest fuel flow rate and torque load on the clutch and transmission. You would think that if it were a return fluid pressure issue that it would be worse in first than other gears.

If it's only in 2nd gear then that set is suspect, but it should be jumping into neutral with worn gears.

If it's only doing it at a certain RPM, then that opens up the field to electric/ignition, but they don't heal themselves. It could be hitting the rev limiter in the igniter box but the indicated rpm on the tach is reading lower than actual.

And it could be starving for fuel and cutting out if the float level in the bowls is too low, has a dirty fuel filter or some other fuel flow issue, etc. It could be a carb issue.

Has the bike set up for a while without being ridden before all this started to happen? Are you using fuel with alkyhol in it?

What exactly are the symptoms? Is it like hitting the rev limiter and the power just falls off? Any grinding or other noises associated with the event? Does it only happen in 2nd? Happen only during hard accel or all the time? etc...

 

Wouldnt you have more torque on the clutch through the higher gears? It would be just like trying to walk up a ramp. Steeper the gear the harder it is to move and if you had to much final gear you would'nt be able to pull full rpm.

I agree that if it is slipping in 2nd it should slip in all or more then one gear. I also agree with tinkerinWstuff and get a video

 

Thanks for all the advice guys, BTW. I spoke to my local Honda tech @ a dealership and he confirmed that it was probably the shift forks, for what that's worth.

I looked at the clutch fluid thru the sight glass many times, and it was nice & light in color, but before I tear into the tranny today I thought I might as well check it again.

And it's as dark as molasses now where it wasn't just a week ago. So, I opened it up just now and filled it with fresh. Speedbleeders made real quick work of it. Like I usually do, I took a q-tip and pushed it around to stir up all the much darker fluid and get the coating of muck off the inside of the reservoir. Used a syringe to get it out of the corners. Man....it was like black coffee. And it got to this point from being light & honey within about 400 miles. Odd.

Anyhow, it's all clean and tight now, and I'm about to take it out and see if it helped the 2nd gear slip issue at all. Here's one other thing I noticed: The "protector" (p/n # 45512-MA6-006) is missing. Maybe it wasn't there in the first place or maybe I misplaced it last time I did this.

So I'm assuming since it's on the fiche I should go get one. Doubt it would change the 2nd gear issue though.

More to report once I run it down the road today here after lunch.

 

It has not set up. I ride it every other week for a full week. No alcohol in CA fuel, so that's not a concern.

It is exactly like hitting the rev limiter, and the power does just fall off. Except it happens only in 2nd and only around 6-8k. No grinding, no noises, so pulsing. 1st gear is A-OK to redline, as is 3rd-6th. No sounds or grinding from any of the other gears either. I can ride OK in 2nd up until about 6 or 8k and it's fine.

 

Thought it was odd that the little metal "protector" was missing, so I opened the master cylinder again and re-checked and found it. On it's edge. Put it back where it should be, and went for a ride.

I WILL say that it's incrementally better, just slightly. NOW I can go easy in 2nd, and slowly ease it up, and although it will still occasionally buck, I can get closer to redline now. BEFORE: 6k-8k it would buck hard, and then spin right to redline, and well past it. If I let off the gas a bit, it would come down and drive normally below about 8k. NOW: I can get it up to about 10k with slight bucking around 6k and 8k, but if I stay committed, I can get further in the rev range and it doesn't buck as hard. about 10k-11k it spins right up and right thru the redline though and all forward momentum stops. Roll off a bit, and ride normally below about 10k.

Shift lever doesn't move in 1st, 3rd-6th, but jumps like hell in 2nd above about 6k. I tried shifting into 2nd and holding the lever up, but it still pulses hard against the boot tip.

 

For whats its worth, I had to completely take the clutch m-cyclinder off my bike and hold it upside down and spray the little return port with brake clean mutiple times before the brown goo was gone. The protector does nothing but keep large pieces off debris from covering the port, however any moisture will lay at the bottom of the resivor (water is the heavier fluid) and collect any foriegn materials (dirt) and goo it all up. Afterward refilling and bleeding the clutch took a while to get a "lever" back.
I was not experincing your issue but I rarely go over 6k revs either, I just commute with the bike.

What kind of oil do you use? Some auto motors oils, high milage and such, have lots of additives that could reduce friction on the clutch plates, so I hear.

 

torque on the clutch?

Take a look at this guy's article on torque and horsepower--see if it makes sense to you (he also compares harley to vfr acceleration). From his explanation first gear produces the most torque at the rear wheel, but the torque on (into) the clutch is only determined by the engine torque and the primary drive ratio.

Torque vs. Horsepower

i'm not following the ramp example, but trying to think about it. It seems that the max load on the clutch disks to cause slippage would occur when the difference between the input torque and output load torque was greatest--maybe that is the situation that Tink described. If the ramp was the load (torque), then put too much load on your shoes (clutch) and you slip when the ramp is steep?

 

Since you found brown goo in the master i'm going back to my original idea of a clogged return port being the culprit and the clutch is slipping. If it were jumping out of gear it would make a hellacious racket.

Before you split the case you might pull the gearshift linkage cover below the front sprocket and see if the shifter drum center is wallowed out.

Chances are you have two issues, clogged return port and bent 2nd gear shifter fork.

 

Honda OEM oil. Gen4 is it? Red label.

 

UPDATE: Sorry this update has taken so long, but here's where things are: I dropped the engine, split the cases, and found.....a bent shift fork. Pretty significant scarring/gouging on one side of one fork, and the peg/dog for 2nd gear that moves inside the long slot to engage the gear has been significantly rounded off on one side. So, all together I need about $500 in parts for o-rings, gears, gaskets, etc, which I have ordered, and I'm sending the tranny out to be up & down race cut so this won't happen again. Should have it rolling out of my garage in a week or so if all goes well timing-wise.