'78 GS750 Heavy Clutch & Adjustment issues

[Holdawayt]

Hi folks,

I hope someone can help with an on-going issue. I bought my 1978 GS750 last year as a restoration project so I've only taken it up for a run up and down the drive.
The clutch has always been incredibly heavy, 4 finger pull is difficult and I'm a fairly big guy.
To get the clutch to disengage at all, I've had to wind the adjuster on the engine side all the way out until it barley screws in, and the clutch lever adjustment is a similar story.
I've replaced the cable with a new one and routed it as per the manual.

I replaced the clutch springs in the basket with standard items just in case someone had fitted heavy duty springs but this didn't help.
While I was there I noticed deep grooves on the clutch basket where the metal plates have been catching so this is something to bear in mind and I will replace the basket in due course.

I also decided to adjust the clutch mechanism on the left side of the engine as per the workshop manual. You're meant to back the lock nut off, screw the adjuster all the way in then back it out a quarter turn. When I did this, and wound the adjuster in, I noticed that when it's set as per the manual (wind it all the way in until you feel resistance then back it out 1/4 turn) it would be impossible to fit the actuator and the locknut as there aren't any threads showing when it was wound all the way in. What does this indicate? I take it something behind that adjuster is wrong. Perhaps the long rod that goes through the crankcase (that I assume this adjuster pushes up against) is fitted incorrectly or is damaged? Does this long rod just pull out once you remove the actuator assembly?

I'll likely take the entire assembly apart but I can't find anything in the workshop manual relating to the rod that goes through the crankcase from left to right so I'm not too keen to go digging.

I don't have the bike here at home unfortunately so any advice will have to be gratefully received and tested when I have access to the bike. I can take pictures while I'm there next but hopefully I've explained the issue well enough in my post to get the ball rolling.

Cheers,

Tom.

[Holdawayt]

This is the part that has grooves worn into it from the clutch plates. I think this is called the sleeve, not the basket - sorry. s-l1600.jpg

[Nessism]

I would check the clutch release mechanism. Maybe something is binding.

[Suzukian]

The adjustment arm is on a screw that pushes in once it's be end adjusted.There's a Spring on the end of that shaft that pushes the Rod back out. If you look at the pic you'll see the Rod goes all the way through to the inside of the adjusting screw. When you pull the clutch, the threads release the pressure on the clutch basket so you can shift/take off. The Spring might not be in place? Only you will know, but both the covers have to come off. You put the clutch cover on last, to make sure the clutch is disengaging when you pull the lever.

suzuki-gs750-1978-c-usa-e03-clutch-release_big3IMG00903061_132f.gif

[erki52]

I'm so glad my GS750 isn't the only one in the world with a heavy clutch. I ended up converting my clutch to a hydraulic set up which has reduced the pull needed to operate the clutch.

[Suzukian]

If the grooves are smooth, your clutch is going to be funky. It could grab, stick, etc. Those surfaces have to be extremely smooth, or you will develop clutch release problems. I have found Suzuki's have really smooth clutch release mechanisms. In the picture you posted, after looking really close, you can see the distortions. That piece is shot. The release mechanism is so straight forward, it wasn't till you stated the irregularities on the surfaces, that I realized how much out of shape they are. Multiple that by all those tabs..........You could try taking a file and smoothing out each slot. Problem with this is there is no way to do it exactly, and some tabs may be touching, while others aren't. What it will tell you is if that clutch now operates smoother, then you proved you need to replace that part. If you do it by hand, carefully, smooth file, it may work for a very very long time, and you could replace it next time you do the clutch pack. IMHO

[rphillips]

I'm having trouble seeing anything wrong with the sleeve in his picture. From what I remember the grooves are usually a lot worse in the basket than on the sleeve. I'm not sure about those 750's as they are operated totally different from the GS1000 and 1100's. But I've ran baskets with really bad grooves, and never had any problems. Always thought it should cause some kind of binding or something, but for me it was barely noticeable if at all.

[zed1015]

This is the part that has grooves worn into it from the clutch plates. I think this is called the sleeve, not the basket - sorry.

It's called the clutch HUB..
Notching of the grooves can be eased off with the use of a file .
If you are careful and don't go any further than the bottom of the grooves they will all end up the same width and the plate load will be spread evenly across the whole assembly.

[Holdawayt]

Good news!

It's all sorted, I managed to find a complete clutch hub, flywheel and fairly new clutch plates for less than some new plates would've cost. Fitted it all up and it's perfect. Still fairly heavy compared to modern bikes but more than useable.

It must've been the old clutch hub, either the grooves left by the plates or something not aligned properly.

[rphillips]

Great way to start the new year... Congrats, and enjoy ... both the bike and the new year.

[Suzukian]

Great!! I thought that basket was catching the tabs.

[unfocused]

Might also look at red circle below. I found mine had rusted and 1 ball was pitted bad with little movement. When replaced, I used a synthetic brake grease for lube- this is the clutch actuator in the sprocket cover.
image.png