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Clutch slipping! questions about friction plates etc. Please help!

Donoman

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Hey guys,

First time poster. First project bike
77cb750k

here's the rundown:
opened the clutch because after I finally got the motor running and the carbs adjusted, the clutch wasn't working. I would pull the lever, it would clunk into first and then when I let go, nothing happened.

I ordered new friction plates and springs and placed them in but found out my lifter plate had a corner cracked off...( I dont know how crucial this part is btw so please enlighten me.) also the friction plates i ordered didn't match the description in the manual. the final plate is suppose to be thicker and have a swirled design but all seven of my plates are identical.

Anyways, after all this finally when i went to ride it it engaged into gear and i had a blast for about a day. the next day I tried taking it out for another spin and it starts to slip a little. then a few hours later I take it for another spin and now its almost completely slipping again. when i put it into first the bike will move a bit but not a lot.

i made a couple of noob mistakes though: i realized i soaked the friction plates in the wrong kind of motor oil, and i think i should have sanded down the steel plates, and i think i might not have tightened the lifter plate enough. so tomorrow im planning on re-opening the clutch and wiping down the plates, sanding the steel ones and getting the lifter plate as snug as possible without damaging the aluminum. if anyone can think of any other possible problems please let me know.

i dont know if i should get new steel plates or not and im not sure if i need that thicker swirled friction plate. and im probably gonna get a new lifter plate as soon as one is on ebay for less than a billion dollars.

sorry for the long post, please help this poor amateur noobie. thanks!
 
The lifter plate should be tightened all the down and to about 80 in-lbs (clean dry threads, less for oily threads). Post a photo and we can tell you if it must be replaced. I would look for a cycle junk yard nearby for that part after finding out how many different years use the same part.

No, one plate does not have to have a different pattern but, quite often you need 1 extra plate with aftermarket plates. Stack the old plates on a flat surface and measure the height, then do the same with the new parts. The stack can be a little (half a plate) thicker, but not thinner.

Make sure you have properly adjusted the release shaft, the lever should have a little play in it.
(follow link for schematic)

For clutch plates I reccomend CycleX
(follow link and scroll down the the clutch kits. The regular ones are after the lock up kit.)
 
The lifter plate needs to be replaced if it is cracked. Easy to break removing and installing. Watch ebay for used ones, new ones are not available.
 
wow thanks for the quick replies!

I didnt get a chance to work on it today but hopefully I will tomorrow or the day after.
I'll try to get pictures uploaded of the lifter plate.

the problem with stacking the old plates to compare is that i think the PO had it installed wrong as well. when I opened the clutch, there was very little wear on the old plates and springs but there was also only 6 friction plates installed and when I looked up the diagram of the clutch according to my engine number it showed 7 friction plates and 5 steel plates and 1 double steel plate so that's exactly how I put it together

I'll try to get a picture of the clutch assembly to show you guys how much space there is after installing the plates again and hopefully you guys can tell me if i need an extra friction plate. if not I have a store nearby that has the thicker swirled one in stock anyways for 12 bucks so I'll probably just get that.

I'm pretty sure I have the lever adjusted correctly because I first thought that was the problem so I looked at endless videos and tutorials for how to adjust it properly and now think I have that part down pretty well.

But until I find a new lifter plate, I was planning on running it on the one that has a little piece cracked off. all four towers screw in and hold the plate and springs in place though so I thought it would be okay for the time being but again, I'm a total noobie so please let me know what the dangers of doing that are.

I'm thinking, after hearing your guys' torque specs, that I'm pretty sure I screwed in that lifter plate too loose and that running the bike might have loosened it which is why it was running okay the first day. I'm hoping its just a combination of that, and glazed steel plates, and the wrong motor oil on the friction plates thats making it slip.

but please, I would love to hear your opinions!

again, thanks for the replies. I'll keep you guys updated!
 
Dirtdigger may be able to explain this better as he has more hands on with these bike but here it goes.

Get these parts in your hands (2 and 5), and put them together and see how the splines slide in. Now with all the disks in that you don't want 2 bottoming out in 5 but you want 2 far enough in there so it doesn't come out when you pull in the clutch lever which pushes 5 away from 2 (5 is the moving part).

honda-cb750-four-k4-usa-clutch_bighu0105e1309_0ad0.JPG
 
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