Clutch, Gears, and Power after Oil Change

Hello everyone,

Just got done last night with an oil change on my 81 XJ650. I had gas in my oil from the PO: http://xjbikes.com/Forums/viewtopic/t=37126.html
I put a new Fram CH6003 (gotta say I love the rings that came with, and for $5 quite a bargain) and some Castrol 4T 20W50 Motorcycle Oil (which is on sale at AutoZone right now BTW...3 liters for $9.75)

I ran the engine for a while and let her warm up after the oil change and went to bed.

This morning I fired it up and noticed that my gears were VERY difficult to shift. I figured the oil probably just needs to cycle through a bit more. Left it running, and all worked out pretty smoothly with shifting eventually.

At a stop light, I noticed that I had the red light creep all of a sudden. I pulled over and looked a bit and my clutch grip bolt had fallen off somewhere. Wasn't too far from home and PO gave me a bunch of spares, so I turned around and slapped one on. Clutch pull feels a bit different now though and feels like the tranny doesn't start pulling the bike til about 60% of the clutch handle is released...odd.

After getting back on my way, I noticed some occasional 'slipping' once getting into 5-6k RPMs where engine RPMs would keep rising when throttle was applied, but no speed increase. This is definitely new.

I am wondering if the oil needs to 'settle' a bit more or should I say more fully saturate the gears...OR if the gas that was in the oil caused some issues with my clutch plates. I already know I need a clutch cable adjustment and lubriaction for sure.

Where to go from here?

 

You probably need to rebuild that 30-year old clutch; the gas in the oil didn't cause the problem, ~30 years' worth of sitting did.

By all means get it adjusted; but if it's both dragging and slipping, (what you described above) it's new clutch time.

 

I can see how that may definitely be the case, but it's hard for me to ignore that these issues didn't start happening until I drained and replaced the oil. No more than 12 hours ago I had full power range all the time with no slip.

But I agree that regardless, it is probably time for some maintenance on that clutch. Lord knows the PO didn't love her like I do and will.

Recommend a full kit or just friction disks for startsies? Any good sources?

 

At the very minimum, friction plates, SPRINGS, and a new gasket.

For parts, I'd recommend XJ4Ever.

 

You rock Fitz. Thanks!

 

Put the other oil back in

 

Hahaha! :lol:

 

I just wanted to put this link here for anyone else that stumbles on this thread with similar problems:

http://xjbikes.com/Forums/viewtopic/t=29541.html

A great write up on clutch inspection and overhaul by bigfitz52.

I plan on using it this weekend to at least see what is going on in there and report back. 8)

 

It's all making sense now. The old oil likely had some 'grit' to it. With removal of that old gritty oil and adding new, the worn clutch components are showing their true colors and the silky new oil is making slippage easier.

Looks like I'm going to be hitting Chacal up soon.

 

Does he need a spring? He has a 650. Are you talking about the external spring? I hear spring on these forums in regard to clutch and my mind immediately goes to that boss clutch spring I am so thankful that I don't have.

 

I'm pretty sure Fitz is referring to the compression springs (5 total) that connect to the pressure plate. No boss spring on the 650.

 

Still torn. I loosened the clutch cable a little for my ride home, and it made the slipping worse! To the point where I had to pull over because I was going too slow. (my thinking was that maybe the clutch wasn't disengaging and loosening it a bit would help)

I pulled over, and tightened it back up and it became driveable again.

I'm probably stretching, but I'm hoping more adjustment on the tighter side may solve this?

 

NO, rebuilding the clutch is going to solve this.

Clutch friction plates are a collection of little tiny brake pads bonded to a metal ring.

When an XJ is standing still, the clutch is half in/half out of the oil (ok, maybe 1/3~2/3) but part of it is sitting in oil, part of it isn't.

When a bike sits for a number of years, the friction "pads" that were oil soaked but no longer submerged dry out, becoming little squares of petrified linoleum. The pads that were submerged become oil-pickled and lose any material cohesion they once had. The little friction pads also tend to "weld" themselves to the plain plates, leaving behind a "memory" of them once they're broken free.

If you take a close look at the pictures of the "pre-refinished" plain plates in my article, you'll see what I'm talking about.

Then we come along and put the bike back in service with no consideration given to this horribly deteriorated clutch pack because we can't SEE it. After a few heat cycles and some nice fresh oil, those 30-year old petrified friction plates are NOT going to grip very well any more.

The clutch springs also tend to "sag" after all that time; fitting new springs just ensures that your new clutch won't slip.

The clutch (friction plates and springs anyway) is one of those things, like brakes, that simply have to be rebuilt to attain reliable operation from a 30-year old bike. In most cases, the original friction plates are far from worn out; they're usually just AGED out. The little friction pads get all black and crumbly at the edges and simply need to be replaced.

If you want the "brand new bike" feel, treat yourself to a new clutch cable at the same time.

 

Alright, so I am taking the advice and ordering my parts to get this thing overhauled.

What should I expect when I get this thing done? Should I take it easy for a bit on the throttle in the beginning?

 

It might be a little more grabby than you're used to. Be a bit ginger to start.

 

x2, we rebuilt the clutch on a buddies suburu sti, and for like a week after, it was like he never drove a manual in his life before, haha

 

Just be sure you soak the friction plates in fresh motor oil for at least an hour before beginning to assemble;

and be sure to "dredge" all of the parts in clean oil as you reassemble.

Take your time and be sure to align the dots on the pressure plate and hub. Use a torque wrench on the bolts, they don't go very tight.

Unless yours has been slipping horribly, you shouldn't notice much difference. You will need to re-adjust the cable after a few heat cycles and a couple hundred miles.

 

Thanks Fitz. She was slipping only briefly in the 5k-7k RPM range...just for a moment before catching again...that is until I adjusted the cable which I assume must have tightened the cable too much because in every gear it slipped ALL THE TIME giving me very low power. Rode like that for about 60 seconds before I said the hell with this!

I really need to learn the proper way to adjust the cable at the handle bar level and at the throwout arm, and I am guessing getting in there will give me a much better understanding with how the clutch system works.

I am guessing that pulling in the clutch disengages the clutch by pulling the pressure plate and compression springs outward which in turn seperates the friction plates and drive plates. If the cable is too tight then the clutch remains partially disengaged creating a loss of power and more slippage. If the cable is too loose, you don't get enough throwback and the clutch doesn't fully disengage when pulling in the handle...causing hard shifting, creeping, etc... Is this correct? How far should the throwout arm swing when pulled?

By the way, I am absolutely loving this. Any excuse to wrench is a blast, and in turn makes my bike perform better...which makes me even happier! Thanks everone!

 

You are correct in the operation of the clutch.

There is a spec for the freeplay in the clutch lever. Mine Seca's even got a plastic cover with a window that shows where the clutch and front brake lever should fall when released. If you put it in that range, and it slips, you won't be able to adjust it, you need to dive in.

When reinstalling the cable, you adjust at the bottom first, with the adjustment nut in the handle bar in a middle position, and get the freeplay close. Then you adjust the handlebar nut to fine tune. If you can't get the proper freeplay, adjust at the engine and then fine tune again.

 

Glad I am beginning to understand it!

In regards to the throwout lever, if all tension is released will it move pointing further down the case toward the rear of the bike? Or is it pretty much "home"? Also, how important is the spring around the throwout arm? Mine is apparently broken...I am guessing it is just a guide, but I want to be sure.

And just to clarify, I am asking not to adjust the cable as a solution as I have ordered the parts for the overhaul. But I am going to need to know this when the clutch parts and new cable arrive