Clutch adjustment when warm

[Superjet]

Hey guys. Simple question here nothing too fancy or complicated. I do the clutch adjustment as follows: back lever nut to perch fully loose then I adjust worm bolt one nut flat back out from lightly seated. Fine tune at perch. Problem is this: cold start all is good but once warm, seems to grab more even clutch pulled in. Wanted to know should I be backing the worm bolt a bit more to allow more room for expansion due to heat? I have an aftermarket clutch perch and it isnt as long from lever to cable as oem. I wonder with engine at temp, expansion is playing a trick on me and affecting freeplay/grab. Any comments guys? Would like suggestions/thoughts.

 

[gggGary]

I think I would go the other way (and do) play with it, but no more than an 1/8 turn from "slack out". I guess the "slack out" starting point is the question. I'll usually snug it good then back off til I just feel the pressure release, then about 1/8 turn. It's simple enough it can be done and played with roadside..... Possible; warped plates will create drag no matter what you do. I will guess running a slipping clutch for very long can warp plates. With the 8 plate conversion in madness we sat in hot stop and go leaving the Peoria racetrack for a solid half hour with no clutch issues. Neutral remained easy to find.

 

[TwoManyXS1Bs]

Have you read this?

http://www.xs650.com/threads/xs650-clutch-pushrod-experiment-tidbits.32267/

 

[Superjet]

Hi Gary I have been adjusting from slight resistance back 1/8 or a nut flat of a turn. I will try it until no resistance and then back off another 1/8. That is what my thought is to creating a little more room for expansion.

Hi 2M I have gone thru it in parts. I do not have the single pushrod, only the 2 part one. When I first got the bike, I took the left engine cover off to discover that the chain had once broken off and hitting the pushrod down leaving a dent on the case below the seal. My seal was leaking, therefore I wanted to replace the seal and replace the oem pushrod too. It is a new Mike's XS pushrod that I have installed. I will see what the indent looks like on the old oem and see if it is ok. I do believe that it is still straight. If this is the case, I will look at both pushrods again. I would feel more comfortable having the oem back in there. I only have about 750kms since the rebuild and am curious on wear to the Mikes pushrod.

 

[gggGary]

Superjet I'm thinking we may not be on the same page. The engine expands when hot (aluminum) the two part rod does nearly the same (much is aluminum) but the takeaway is that the amount of drag due to (lack of) plate separation increases when the motor gets hot. So less free play, not more freeplay should help. There are several gotcha's, one may be your aftermarket perch/lever the stock set up is designed to create quite a bit of cable movement. I measure 1 3/16" pivot to cable end C to C. I checked madness and have only 1/4" freeplay at lever end cold. Resto has 3/8" ie both are rather tight, cold.
As always; cable design (Motion Pro?) lube, oil til it comes out the other end, minimal bends (stock route not always best route). 2many's thread referenced above is only one of his many on clutch action issues and "fixes".

 

[Superjet]

Sorry Gary...I replied to you as Jim in my earlier post (I changed it)...sorry about that. The clutch assembly is expanding more than allowed freeplay and causing plates to not fully open causing drag. I do believe that is what you are saying. Please correct me if I have it wrong.

I have purchased yesterday an used oem perch and lever from another member on here. I have motion pro cable lubed, routing to avoid binding along with worm gear properly lubed and rebuilt. The cable operation is smooth that I know. Thanks J-C

 

[gggGary]

Jim would be the one take offence..........
Ps what engine or "clutch year, plates etc" do you have?

 

[gggGary]

On resto (stock 79 2F0) first clutch release of the day I've started getting an odd "dry bearing vibe-whir" for a second, that's it, only symptom. Oil recently changed, no difference.

 

[Superjet]

Stock 83 6 plate nothing fancy.

 

[5twins]

The engine cases expand more than the pushrod(s). That means the distance between the worm and the clutch grows but the length of the pushrod(s) doesn't do so as much. That adds freeplay which means less clutch plate separation.

 

[Superjet]

Great! Thanks guys. I will adjust to see how it does when fully warm. Gonna install the used oem perch and lever once it gets here. Worst case like Gary said is to adjust on the side of the road once fully warmed up.

 

[gggGary]

The later engines used a longer arm on the worm for a lighter clutch feel. That also shortens worm travel, many of the manly men round these here parts, drill a hole a bit closer and move the cable in, similar to the early model set up. twomany has an in depth thread.... LOL.

 

[5twins]

Well, you should be able to do a little additional adjusting once hot if need be with just the perch adjuster. But that's kinda the whole trick to these - getting it set up initially tight enough so re-adjusting once hot isn't needed. But, you can't set it too tight or the clutch is going to slip on you. You want to do the majority of your adjusting, as much as possible, down at the worm, then finish up with just a little fine tuning up at the perch. You don't want to, or have to screw that adjuster out very much at the perch.

Here's the technique I use for setting the worm on a cold motor. I call it "fanning" the clutch lever. I tighten the worm screw until it makes contact then I start "fanning" the clutch lever. This means pulling it in just through it's freeplay until it's taken up, releasing, pulling through the freeplay again, releasing, etc. I don't pull the clutch lever all the way in, just through it's freeplay range. What this does is stack the pushrods and balls tightly together, taking up any slack and forcing any oil out from between them. If you keep turning the worm screw in while you're "fanning" the clutch lever, you will find that you can sometimes get it almost 1/4 turn tighter. After all this, then I back the worm screw out about 1/8 turn and lock it down.

 

[Superjet]

5T I have never read this technique. I will give it a try for sure! The experience on this site blows my mind. Thank you for sharing this.

 

[Jim]

Sorry Gary...I replied to you as Jim in my earlier post.......

Just don't call him late for dinner....

 

[TwoManyXS1Bs]

On resto (stock 79 2F0) first clutch release of the day I've started getting an odd "dry bearing vibe-whir" for a second, that's it, only symptom. Oil recently changed, no difference.

Ruh-roh.
The mainshaft double-row bearing, behind the clutch, handles the lateral force of the pushrod. There's no oiling feed to that bearing, it's strictly splash lubed. Listen closely while applying light clutch lever pressures, without full lever pull.

Then, the next day, lean the bike way over to the right, and do that again...