Slipping clutch.. Simple fix?

I know this is a very common thread and has been repeated tons of times, sorry to do it but i havent found a thread that answers my question.

I have a 98 yz 400 with an AVS clutch on it from the previous owner.

i was out ridding it today and noticed that the clutch slips while under hard power in the top gears. :crazy: but stays hooked up down low.

my question is, is there a way to fix this by putting in stiffer springs, or pulling out the clutch and doing somthing simple to it?

the clutch has been great it just tends to slip a little when i hammer the gas.

Thanks, Michael

what kind of oil r u running in her

Vavoline 10-40 W

and i topped it off a couple of weeks ago with some Pensoil 10-40 W (with adaptive molecules, but its not a friction additive)

I have heard of folks using washers under the clutch springs which will make it stiffer but help the pressure plate apply more force.

You may just need a new clutch!

so even making the springs stiffer wont help much?

I know this is a very common thread and has been repeated tons of times, sorry to do it but i havent found a thread that answers my question.

I have a 98 yz 400 with an AVS clutch on it from the previous owner.

i was out ridding it today and noticed that the clutch slips while under hard power in the top gears. :crazy: but stays hooked up down low.

my question is, is there a way to fix this by putting in stiffer springs, or pulling out the clutch and doing somthing simple to it?

the clutch has been great it just tends to slip a little when i hammer the gas.

Thanks, Michael

I have had a few of them come back to life by lightly sanding the friction plates. I dont consider this a permanent fix, but I have dont it before when shoplifting was the only way to fix it right.

In the old days we always had a ton of goofed up spark plugs around. The two stroke plug washer was always the same diameter as the clutch springs. You could use the washers to preload the spring and get by for a while.

ok, thanks ill try that :crazy:

now should i just use one washer, or two?

about 6, and you should look into changing your power steering fluid while your at it.:crazy:

since when does a YZ inclue power steering fluid?

do they? :crazy: lol

When I rode a YZ250 2-stroke, I would add a extra steel clutch plate. It worked pretty good.

i see, can you find a single plate for sale?

i see, can you find a single plate for sale?
Sure, Yamaha sells each plate individually.

Also, when you replace your clutch it is worth it to buy OEM Yamaha.

ah i see,

well thank you guys for all the great answers! :crazy:

well i pulled out all the plates, gave the friction plates a light sanding, and added a washer to each of the springs.

went to put it all back together...

and now the cluch spreader wont disengage the cluch. :crazy:

i put it all back together the same way i took it out, and aligned the pressure plate up with the mark on the clutch boss, just like the manual said.

and it just wont disengage now :D

what did i do wrong?

The washers are probably causing the springs to coil bind before the pressure plate has traveled far enough for a good release. Remove them.

rough up the steel plates lightly and remove any chatter marks on the inner and outer baskets ,forget packing the pressure plate with washers it will only crack the spring recss out of the pressure plate in time and cost you a new plate or more .even a change of g/box oil might fix the problem .also when you refit the plates make sure the sharp edge on all plates face inward as you will see it helps them engage smoother

I would take the springs out and measure the length. The springs shorten during time. My first springs hold about 150 hours. My second (oem) springs were after 50 hours 3mm under the limit. Before getting washers or stronger springs, check the springs. This would be the easiest fix. Does this clutch slipping happens in one or two gears at high load or in every gear? Sometimes it is a indicator for a worn transmission, when it happens only in one or two gears.

The washers are probably causing the springs to coil bind before the pressure plate has traveled far enough for a good release. Remove them.

well the problem isnt the springs, its the pressure plate seating.

its like the pressure plate wont seat all the way. (this is all without the springs in)

i have tried every which angle and set up. And it all matches the pictures in the manual perfectly.

and i have taken the entire clutch appart, and put it back together twice :D all the while carefully following the manual.

it just wont disengage in the end. :crazy:

ill go take some pics now, that shoud exsplain this much better.

Here are some pictures i took.

like i said, i pulled the cluch out and put it back the exact same way i took it out the first time. (which i cheked to make sure was right with the manual)

Heres what it looks like just with the cover off:

2.jpg

And here are a couple with all the plates in, just minus the pressure plate:

3.jpg

1.jpg

and one with, the pressure plate ready for the springs.

5.jpg

Assuming that you understand that the arrow at 12:00 on the pressure plate in your first picture must align with the dot at 12:00 on the boss in the second picture, try disconnecting your clutch cable to see if you have any better luck. If that doesn't work, remove the push rod completely just to see if the pressure plate will sit down where it belongs.

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