Dry clutch?

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
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Kiwi Rider
Posts: 45
Joined: Thu Sep 05, 2024 6:47 am
model: 750 Sport
year: 1988
Location: Southland, New Zealand

Dry clutch?

Post by Kiwi Rider »

Am I correct in assuming the clutch runs in a dry compartment on the 750 sport? I ask this because on the wkd my bike ended up on its side after a rider came off in front of me and I had to take evasive action, initially on to the grass but ended up in the gravel trap which is harder to keep it upright in.
When we picked the bike up there was oil dribbling out of the bottom of the RH case cover. Initially I thought I had damaged it but on closer inspection there appears to be two vent holes on the bottom. Ive never heard my clutch rattling or squealing like a dry clutch so I am a bit confused. I'm guessing the oil transferred through a galley from the other side of the motor when it was laying on it's side maybe?
Kiwi Rider
Posts: 45
Joined: Thu Sep 05, 2024 6:47 am
model: 750 Sport
year: 1988
Location: Southland, New Zealand

Re: Dry clutch?

Post by Kiwi Rider »

Well I finally got back to working on the bike after a four month hiatus over winter. First thing I did was rip out the clutch and yes, it is a dry clutch. Funny, I've never heard it rattling away like some of them do. Both the fiber plates and the steels look pretty good so will give them a sand up and a file up respectively and put them back in. The clutch housing and inside of the side cover took a bit of cleaning. That black stuff is mongrel to get off.
Next job is valve clearances which I should really have done when I first got the bike.
Mc tool
paso grand pooh-bah
Posts: 1974
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Riverton New Zealand

Re: Dry clutch?

Post by Mc tool »

That black stuff should be dust , if its sticky there is oil getting in there , so check the seals behind the clutch ....they are standard size ( like Saeco wilsons ).
There is a difference in the later dry clutches with the slave next to the sprocket ..... they do rattle . The Paso style with the slave in the clutch cover puts the axial load of the input shaft and clutch basket in a different way and they are sorta self dampening . Have a look at where the axial loads are when the clutch is engaged and disengaged and you may see why it doesnt rattle
I wish I was young again............Id be heaps smarter than last time
Kiwi Rider
Posts: 45
Joined: Thu Sep 05, 2024 6:47 am
model: 750 Sport
year: 1988
Location: Southland, New Zealand

Re: Dry clutch?

Post by Kiwi Rider »

Cheers for the info mate. It wasn't sticky, more like years of dry baked on clutch dust. The reason I went in there was because at my last track meeting before winter a rider fell in front of me and I ended up riding off track to avoid him and into the gravel trap and the bike ended up on its side. Back home I saw a few drops of oil dribbling out of the bottom vents on the clutch cover.
Mc tool
paso grand pooh-bah
Posts: 1974
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Riverton New Zealand

Re: Dry clutch?

Post by Mc tool »

I would be wanting to find out where the oil comes from. Even a slow weep from a seal will dirty up the clutch . Its either oil or clutch fluid and you dont want either in there.
I wish I was young again............Id be heaps smarter than last time
Kiwi Rider
Posts: 45
Joined: Thu Sep 05, 2024 6:47 am
model: 750 Sport
year: 1988
Location: Southland, New Zealand

Re: Dry clutch?

Post by Kiwi Rider »

Rodger that. Once I've got the valves done I'll fire it up with the clutch out and see what I can see.
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