stm slipper problems

[roderick]

When my bike is cool clutch works like it should, when its hot it will not fully disengage and eventually shift hard.

Before installing I searched about all the installs and problems people had. I was very careful looking at the diagram and reading directions. I was careful to align all the parts correct and remove the two spring washers. I am sure I did not mess up the install but anythings possible. It acts as if the slipper assembly did not draw itself tight to the washer and basket.

I bought this clutch from another member who had the same problems I am having now. No solution was found. Also the hub that mounts on the shaft was very tight for me and him, very tight.

OEM basket, plates. Silkolene 15W50. Cable freeplay cold and hot. Full pull of lever when hot will not free up clutch. With engine hot and off pushing the bike in gear offers much resistance.

does anyone know the distance from the inner hub surface to maybe the basket peaks. this would let me know if I had not seated the hub fully.

[iowaBClivewire]

Also the hub that mounts on the shaft was very tight for me and him, very tight.

can you find ware it is binding up

[Wayward Son]

are you sure the "ovals" are lined up?

[roderick]

The machined spline hole is about .006" to small. I found freezing both the shaft and the hub gave the least resistance but still required much force.

I made very sure to line up the "ovals" because some of your other posts.

I did a dry assembly off the bike to understand how it all worked then put it on. It was put on with engine out on it's side for ease of use. The basket was not removed.

I'll pull it apart today and confirm my install then update.

What springs do you guys have, my box says mx on it and 120kg primary don't know secondary yet

[Wayward Son]

the really ealry ones were very tight on the shaft.

we use the springs as delivered.

are you suing stock sclutch plates? checked the pack thickness? that is critical.

[roderick]

Stock plates, I remember checking thickness but will do it again and document.

I'll get with STM about difference between motard and mx springs.

[Wayward Son]

it only the secondary spring thats different.that just controls how much they slip under heavy decel.

[roderick]

Clutch pack measures 34.94mm, in spec.

I rode the bike last night and this morning the clutch was not as oily as I would expect.

I did not remove the basket to install the slipper but I am doing so now to check the oil pump gear.

I have about 40 miles on the bike so far and the oil level is good. We shall see.

Had a thought, if I have oil in the frame when hot and not when cold wouldn't that mean it's pumping oil?

[Wayward Son]

yes,you can also check by taking the small bolt out above the CCT and running the motor.the oil should flow out briskly.

[roderick]

well after loosing 2 balls in the engine, spending hours debating what to do, luck must be on my side. I was able to find and fish out both balls and start the bike and eddie you are right "briskly" is a good word for the oil flow.

So my plastic oil pump gear is working.

Assembly of the slipper was correct as far as I could see. My only question would be with the convex washer the nut could not fully seat the hub until the washer was collapsed which must happen at greater than 50 ft-lbs.

I used a pic tool to feel around between the hub and basket and check for free play on the washer. Seemed to be none.

I gave the hub a few more wallops with the dead blow, no visible movement.

does the hub surface line up flush with where the treads stop on the shaft.

I drained the oil into a clean bowl and replaced the filter checked the screen for plugging, none. The oil looked like first oil on a rebuild, metalic flake but nothing magnetic.

I'm still working on why the clutch throw is not enough when hot. It's either the whole assembly is too thick or my plates are warping when hot. or something else

Anymore ideas, this is my job tonight then I'm off to MCR suspension for a rework on my SM and ice boingers.

[Wayward Son]

sounds like its on as far as it can go.

so your issue isnt that its slipping it that it drags.

the lever has the normal amount of free play?

[roderick]

Correct it drags.

I made sure there was free play when I set it up and confirmed I still had a little when hot.

[Wayward Son]

you are torquing the nut or just tightening as tight as it can go?

when the clutch plates are out does the inner hub spin freely?

[roderick]

about a 1 sec. rattle with an impact. I do not have a tool or used plates to make a holder with.

if you mean plates removed then yes it spins very free.

I have not assembled the clutch and operated it on the bike while watching it yet.

it will be multiple days before I get back to you. sorry and thank you

[Wayward Son]

no worries.

have you moved the clutch arm on the splines?

[roderick]

yeah I tried that cause my cable looked stretched, no difference.

I got a suggestion that I may have enough wear and tear on the basket to be affecting the action. Didn't look like it to me but I was not investigating.

I will be inspecting the inner hub tonight at work but won't be able to check the basket till tomorrow.

continue with the basics something will show up.

[roderick]

Well the hub has the same tolerance problems the inner press plate has.

Everywhere that a slot is cut in the hub (for lubrication?) binds up the steel plate teeth.

All around the hub the plate floats except the area at these six slots. If the spline depth was a couple thousanths more it looks like it would work.

Next question, has anyone delt with STM direct?

Are they willing to work with you?

I clearly have tolerance issues in a couple places but I don't know if they would exchange or make me buy.

If I have to buy then I will adjust it myself, I just don't want to modify then find out that affects their amount of help.

[Wayward Son]

FMF is the north america distributor.

ive never had a warranty issue with one so i cant say for 100%.

[roderick]

If anyone is interested STM sent me new warrenty parts right away. My clutch was one of the very first batches and somehow my clutch with incorrect dimensions made it out of the factory. They were well aware of the problems I was having and sent the warrenty parts out express. I had them in 9 days from Italy and that was routed through Lockhart Phillips.

All I can say is STM is an awsome company to deal with and the slipper reminds me of that everytime I'm on the bike.

Thanks Eddie for helping me diagnose the problem.

[Wayward Son]

nice!