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Clutch Slipping at high RPM

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I noticed on my last ride that it seemed like my clutch was slipping at rpms over 6.5k. It only did it in the higher gears 5/6. I've read on this board about removing the excess oil in the resevoir, I tried that but it didn't seem to work. Funny thing is it doens't do it in lower gears when I'm hammering it which is where I'd expect it to slip. I don't abuse the clutch while riding either.

The bike is an '06 TE450 with 600 miles on it, and I use Maxima 20-50w changed at 300 mile intervals. I'm not too familiar with juice clutches so any help would be appreciated.

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A clutch inspection is about15 minutes of work. I would recomend it. Hydralics are what is used to compress the springs instead of a direct cable. I suspect your hydralic system is fine.

It makes sence that the clutch doesn't slip in lower gears and does in higher gears.

You said it slips above 6500 RPM which is a mid throttle to full throttle twist that causes it to slip. In lower gears the ratios are lower which creates a scenario where it is easier for the clutch/engine to hook up with and without wheel spin. When you roll on the throttle the same way in 5th & 6th all the power that the 450's make is hitting the drive train when it has more drag/power requirements.

Think of it this way. It is easier for 5 HP engine to pull 50 lbs up a hill at 5 MPH than it is to pull the same weight up the hill at 30 MPH.

I hope my explainaton made sense.

Take the tank off or not depending on how much fuel is in there. Lay the bike on its side. Pull the clutch inspection cover. Pull the bolts holding the pressure plate on. Pull out the discs and plates and see what they look like. If they are bad then just go pick up a set and put 'em in. I wouldn't think the springs would be bad.

I don't know if your oil is a full synthetic or not. I have always believed the tale of guys using full synthetic oils having clutch problems in high HP 4T's. I use a synthetic/Dino blend.

I would bet it is your clutch plates. Shit happens.

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Thanks for the explanation, makes good sense to me. I just have a hard time believing that the plates would be smoked this early, with only 600 pretty easy mile on them. Is there any way to adjust it? I believe it uses mineral oil at least that's what it says on the resevoir.

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There have been a couple reports of guys with the clutch master cylinder fluid reservoir being too full. When it gets too hot the fluid expands and partially disengages the clutch leading to slipping and premature failure.

At least that's the story I heard.

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There have been a couple reports of guys with the clutch master cylinder fluid reservoir being too full. When it gets too hot the fluid expands and partially disengages the clutch leading to slipping and premature failure.

At least that's the story I heard.

Sounds like it could happen? That is why the full line is about 10% less than full capacity. Just check your level and make sure it's not overfull. Is that Maxima you're running full synthetic?

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Too high of oil level is the first place I would look, maybe the second!

I have never experianced the overfull res deal, not shure I guoing to buy into that theory but I guess you gotta experince it first?

The synthetic oil can be a problem, should run a semi synthetic.

I have had zero clutch problems on mine so I have hardly looked at it but a comon problem/cure is to drill more holes in the clutch cover (the aluminum piece that the springs push in) to let the centrificle force sling the oil out of the clutch.

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That happened to my 05 TE450 while in baja at around the same mileage. I backed off the red knob on the clutch lever to increase the free play. After that it has been fine.

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The oil is a semi-synthetic blend. I doubt it's the oil but you never know. I'm going to try the red knob a bit since I did mess with it a little. The grammar in the manual is pretty bad so sometimes it's hard to see what they are getting at. Is that all is does is adjust free play or does it serve some dual function like engagement point?

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The red nob adjusts the biting point. Ive had this with my bike when Ive been ridding for a bit on it i change gear and it seams like i haven't changed gear it just revs more and doesn't actually go anywhere its like its not disengaging properly so ill give some of the suggestions ago on my bike this weekend cheers Ricky

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The "too much fluid in res" thing can happen. When the fluid heats up, it expands and if there is no room in the res for it to expand, it expands in the line cause the acctuation (partial). Same can happen to the brakes. I always fill mine to about midway between the low/high marks to eliviate that. Even though the clutch fluid doesn't heat up as much from use like the brake fluid does, it still gets pretty hot just from conduction of the engine heat into the slave which is transferred to the fluid.....

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Ive just been in my garage and my clutch seems to be fading, it has hardly any pressure behind it but i haven't started the bike like it yet. could air get into the line as i bleed it awhile ago and it was fine and today its not but i will have to see what its like when the bike is fired up any info would be great cheers Ricky

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