Higher ratio clutch lever and perch

[56nomad]

Hi all,

I'm looking to replace my original '81 Special clutch lever and perch assembly with one having a slightly higher ratio so as to give an increased cable pull. I'd like to retain the clutch micro switch. I accept the higher ratio will increase the hand effort required. Can anyone recommend a readily available OEM (any manufacturer) assembly that I could find in a breakers yard?

I see that 5twins uses a Kawasaki KZ assembly primarily for decreased pivot wear. As a by-product, does this one have a 'longer' pull than my original?

Thanks for any suggestions.

 

[gggGary]

wouldn't it be easier to move the pivot hole on the worm arm inwards a bit? weld the hole shut and redrill or get the 2 holer arm Mikes XS sells. 2many has a thread on doing this and some other clutch fine tuning tricks

 

[56nomad]

Hi Gary,

My worm centreline to clevis hole centreline distance is already at 1 3/8". I've not got an earlier worm assembly to try and I don't want to modify my only good one so a replacement lever with a higher ratio is the next alternative.

 

[TwoManyXS1Bs]

1-3/8" is already about as short as you'd want to go. Is there a reason you want more worm travel?

 

[56nomad]

Hi TwoMany,

Yes, I'm trying to improve on that old problem of clutch drag and neutral selection when hot. I've read your articles and many posts on this subject with interest and have implemented what I could but to little effect.

I've ensured that everything is slick running and adjusted correctly. The OEM lever and perch are not worn. The clutch plates are orientated in the same direction to prevent galling (the 'sharp' edges of the stampings facing inwards). The clutch drum ears are not grooved. I previously ran a one-piece clutch rod for stability at the seal but it made clutch drag and selecting neutral when hot worse. (My opinion of why that was is that the one piece is steel which expands to lesser extent when compared to the total of the expansion of the OEM 2 piece steel/alloy and ball bearing assembly. Agree?) So I thought I'd try to find a lever assembly that would give me slightly more cable pull and see what that did.

I'm open to any and all suggestions but I don't intend to go in the hydraulic direction.

 

[XSLeo]

I have searched for the same thing with no luck. I did swap the lever and perch of an 82 Seca. It doesn't pull more cable but sets at a different angle. The cable points more forward than the stock perch.
I have found proper adjustment with a good lube of the worm and cable do about as much to cure the issues you describe.
I prefer the oil and funnel method of cable lube, those spray lubes that use the clamp on the cable things don't work very well. t\The lube isn't slick enough and don't last long.
The clamp on thing works ok for cleaning the cable. Use degreaser or carb cleaner to spray cleaner through the cable with the clamp on thing. Let it drain then use the oil and funnel method as described in your repair manual. I like 3&1 oil. It's a bit light but is quicker to use than motor oil.
I use the one piece rod and a worm with a short lever hole. I adjust as the book describes but at the point I adjust the worm screw I spin the screw in/out a few times to get a good feel for the tension of just the screw turning. This way I can get a better feel for when you first feel the increase in tension as you turn the screw in. This is important to feel. This is the point that all free play has been removed from the mechanism. Now you need add back in a bit if free play. The book calls for 1/4 turn out, I feel that's a bit much. As you turn the screw the nut turn with it. I turn it back out one flat of the nut.
I then adjust the cable at the lever for 1/8 to 1/4 free play.
This works well. This diminishes the clutch drag enough to find neutral easily.
Leo

 

[TwoManyXS1Bs]

You're right about the pushrod. Have a look here:

Clutch pushrod experiment and tidbits

This may also be of interest:

Clutch cable experiment and tidbits

But, to really know what's going on, you may want to make one of these:

Clutch worm rotation gauge

Clutch worm depth dialgauge-post90
Clutch worm depth dialgauge-post91
Clutch worm depth dialgauge-post92

There is a limit in how far you can go. One restriction is when the seal cup contacts the oil gallery bulge between the alternator and pushrod.

A future experiment I had planned to do was to square-off/straighten the interface faces of the pushrod mushroom head inside the pressure plate. Requires a bit of lathe work for that. Got the idea from some older posts/pics here of questionably distorted surfaces where that mushroom head fits into the pressure plate, and the possible uneven lifting of the pressure plate.

Speaking of which, are all your clutch springs the same length? You want that pressure plate to lift uniformly off the plates...

 

[5twins]

I was hoping for a higher ratio and more plate separation with the KZ perch assembly but unfortunately that didn't happen. There was no improvement in shifting or neutral finding. All I got was the improved wear resistance of the wider perch pivot but I'm not complaining. It's a good thing and I don't plan on going back to stock, ever.

I'm always on the lookout for simple little tweaks that may help. My latest is an XS1B shift lever. I happened to get one on a motor I took in trade for bike work and upon comparing it to my '78 original, noticed it was slightly longer .....

Longer length means more leverage and that could possibly ease shifting and neutral finding. Well, I'm happy to report it does help a little. The original doesn't make it past the "H" in the Yamaha name on the cover .....

The XS1B lever extends out midway through the "A" .....

The orientation of the splines is also slightly different, making the XS1B lever sit just a tad higher. I like it better raised this little bit, easier to get your boot under. An easy way to I.D. one of these early levers is the pinch bolt. It goes in from the top .....

 

[chizler62]

Put a EZ clutch cable on it. If you don't like it out where it can be seen order a small cable kit from motion pro and hide it where you'd like it.

A lot of old metric bikes are know for these problems. You can get one and a custom can cable kit for under $100.

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[gggGary]

Once or twice a cracked nylon insert in the worm has taken a while to diagnose. That tends to severely limit how far the clutch will release.
After that
I am with the lube and adjust faction. There is a liner in the engine end elbow on the cable than can wear through and cause high clutch drag. Bike on the lift now has a cable with a black elbow that seems to have even more bend than the stocker. When I picked it up Tuesday the clutch cable and worm adjustment was so bad it wouldn't even creep while running in gear with the lever released. A quick clutch setting identical to the way XSLeo describes and it was back working perfectly even while limping it through a flat spot in the carburation a mile wide. We'll get back to that as soon as the front end goes back together with a brake overhaul and new bearings.
Just saying I have owned, ridden quite a few of these and the main issue I typically run into is clutches that are no longer strong enough for the HP the engine makes.

 

[56nomad]

Well that's given me much to read and think about, thanks, but after reading though some of it I doubt if I'll be able to come up with anything new. I'd still like to try a higher ratio clutch lever/perch sometime if I could identify one, though. Anyone?

 

[5twins]

Yes, I agree what this clutch needs is more plate separation. Unfortunately, there's not much room under that right cover to allow for much more. As it is now, with the clutch disengaged (expanded, plates separated), there's maybe a MM, maybe 1.5mm of space between the pressure plate and the inside of the cover.

 

[56nomad]

Yes, I agree what this clutch needs is more plate separation. Unfortunately, there's not much room under that right cover to allow for much more. As it is now, with the clutch disengaged (expanded, plates separated), there's maybe a MM, maybe 1.5mm of space between the pressure plate and the inside of the cover.

I wouldn't have thought it'd need anymore than a further 0.5mm to enable a clean separation. Unfortunately, anything close to that small distance is proving elusive (as is a lever/perch!!) despite TwoMany's and other's hard work.

My latest is an XS1B shift lever. I happened to get one on a motor I took in trade for bike work and upon comparing it to my '78 original, noticed it was slightly longer .....

Longer length means more leverage and that could possibly ease shifting and neutral finding. Well, I'm happy to report it does help a little. The original doesn't make it past the "H" in the Yamaha name on the cover .....

I'm using rear sets with a 150mm long lever (with 1:1 sub-levers if you get my drift) which I think is shorter than stock. I'd compare but I've not got one anymore. If it is shorter then that's probably not helping.

 

[chizler62]

If you're looking for an easier pull put a ez-clutch cable in. If you're looking for an easier pull and us more cable lenght. Just drill a second hole for the cable barrel in the lever and file a slot for the cable. In fact someone use to sell a lever like that for rear atv parking brake.

 

[56nomad]

Hi Chiz

Unless I'm not understanding your suggestion, there isn't enough space on the lever further out from the original cable barrel hole to drill another. Even if there was the cable would no longer be in line with the perch adjuster and cause extra friction I suspect that the ratio change would be too great. Do you have a pic of that ATV lever?

 

[chizler62]

Wayne at PEP doesn't sell them anymore. I'm certain if you dig thru Parts Unlimited you'll stumble on a lever and perch that'll work.

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[56nomad]

Hi Chiz

I see what you're suggesting now. That mod will decrease the effort at the lever and decrease the amount of cable pulled. I want the opposite: to pull more cable at the [unavoidable] cost of an increased effort at the lever.

I'll take a look at Parts Unlimited all the same.

 

[56nomad]

Oh dear, the dark forces of the wicked hydraulic clutch goblin are too strong for me to resist! Unless the good cable clutch fairy can find me a high ratio perch then I'm lost .......

 

[nh-jk]

650central.com sells one, call him. He is a great guy full of knowledge.