Kicker Bushing Project (woolgathering)

[3Phase]

I don't know if this would actually work but there I was, sitting in the garage with nothing to do. I was looking at some of the parts sitting on the work bench when I had a thought! I let it roll around inside my head for a little while like a BB in a boxcar, then grabbed the parts and took some pictures.

As usual, click any of the images to get a larger version.


Make a kicker bushing:


A bad NTN NA5904 needle bearing and its inner race along with a '78/'79 XS1100 kicker assembly. The outer needle bearing race was intentionally broken to show the width of the outer race.

The kicker assembly shaft looks like it's the same diameter as the rear axle.





Amazing!

The old inner race of the NA5904 is a perfect slip fit on the '78/'79 XS1100 kicker assembly.





The clutch cover kicker hole would need to be bored out before the inner race could be pressed in.

The ID of the old inner race and the ID of the hole in the clutch cover for the kicker shaft are identical.

It looks like there would be enough material left after boring the hole to support the kicker without breaking the clutch cover.





The kicker assembly shaft is stuck through the NA5904 and into the clutch cover.

Unfortunately the OD of the needle bearing outer race is too wide and cannot be fitted into the clutch cover.





Should I just go back to counting sheep while I wait for some new Barnett clutch springs or would this work?

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[rdmcguy]

Kickin it!!!

It looks like it could work,..If not a bearing maybe oilite? (sp)
In looking at the case itself ... the webbing Was put there for a reason.
And.. ALL the bikes I own with kickstarters just ride on the case with no bearing or bushing..Big Honda singles Cams just rode on the cases.

[CRXSi90]

I don't have anything super constructive to add, but since this is about woolgathering...

Bushings and sleeve bearings are usually made of a different material than the surface which they are supporting. I guess it's to prevent galling of similar materials and also isolate most of the wear to the (replaceable) bearing rather than the shaft. That said, it would take a lot of kicking to wear out the steel shaft on steel bearing, as compared to steel shaft on aluminum case. However, if it were me, I'd probably try to go for some kind of brass or bronze bushing.

Never having been in there myself, what's the sealing situation? Anything?

[3Phase]

I like to re-use old parts instead of throwing them away!

RD,

I know what you're saying but the bore in the clutch cover has just started to show a little wear after kicking the engine for almost five years now. Well, that's what started the spinning wheel spinning, at least today anyway.

I'm more surprised that the rear axle and the kicker shafts are the same diameter than worried about wear on the kicker assembly or the race/bushing. That old race has survived over 70,000 miles getting beat on by the rear axle, what's a kicker going to do to it? <laughing>


CRXS,

Sealing... sealing the kicker shaft and the clutch cover? There's an oil seal in the outer part of the clutch cover and the race is short enough that it wouldn't reach the seal unless I totally screwed up boring the hole. Even then I could just not press the bushing in far enough to touch the oil seal.

If I can get it bored I'm thinking about using some that Loctite/Permatex permanent sleeve retaining goop so the bushing doesn't get any bright ideas about coming out of the hole once it's pressed in.

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[motoman]

See no reason(or any given as yet) why it wouldn't work.
As far as loosing a bit of material from housing, being a ROTATING needle bearing assembly, any directional load applied(kick-starting) is gonna be dispersed full cicumferance of needle bearings as opposed to a fixed steel/bronze bushing. IMO, there looks to be re-purpose work for that bearing once it retires from it original intended stress load.

As for 'woolgathering'...........................stick to your day job.........

[3Phase]

See no reason(or any given as yet) why it wouldn't work.
As far as losing a bit of material from housing, being a ROTATING needle bearing assembly, any directional load applied(kick-starting) is gonna be dispersed full circumference of needle bearings as opposed to a fixed steel/bronze bushing.

Only the inner race will fit. It's removable. I wish I could use the entire bearing but it's bigger than the boss cast in the clutch cover:-

IMO, there looks to be re-purpose work for that bearing once it retires from it original intended stress load.

As for 'woolgathering'...........................stick to your day job.........

Yeah, yeah, yeah ....

I'm also fixing up the XJ alternator to fit it to the XS. One of the stator leads got smashed and cut when the bike was slammed into the guardrail post so that has to be fixed and I'm not sure the XS Rectifier will handle the extra current for longer than it takes to say, "Yay! It works!" (fade to black)

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[James England]

That looks like a good idea to me. It's got to be better than a steel shaft rotating in an alloy housing and I therefore would not be concerned re it not being a bronze bush or whatever. If you get the sealing side of things sorted out, I'd say it's an excellent idea and a good use for part of a broken wheel bearing.

Personally, I've never liked the OEM setup with its lack of bush or bearing. It is, after all, supposed to be an emergency kickstart but many people use the kickstart regularly.

Do it! Get a seal in and post pix!

[crazy steve]

...Bushings and sleeve bearings are usually made of a different material than the surface which they are supporting. I guess it's to prevent galling of similar materials and also isolate most of the wear to the (replaceable) bearing rather than the shaft.

I doubt that is much of an issue as Yamaha used steel bushings for their kickers on other bikes (notably the 650 twins) that were designed as primarily kick start. In this case, that inner race is probably harder material than the shaft but given the splash lubrication present and intermittent use (even if using the kicker full time) wear should be minimal.

I'd be more concerned with weakening the cast boss in the cover after machining it out for the bushing. Again, comparing this cover to OEM covers designed for kick-only bikes, Yamaha skimped on the material around the cast boss for the shaft.

[3Phase]

I doubt that is much of an issue as Yamaha used steel bushings for their kickers on other bikes (notably the 650 twins) that were designed as primarily kick start. In this case, that inner race is probably harder material than the shaft but given the splash lubrication present and intermittent use (even if using the kicker full time) wear should be minimal.

You know, "splash lubrication" is probably a euphemism. The kicker is directly behind the clutch and at high RPM it's more like "oil plasma lubrication" than splash.

I'd be more concerned with weakening the cast boss in the cover after machining it out for the bushing. Again, comparing this cover to OEM covers designed for kick-only bikes, Yamaha skimped on the material around the cast boss for the shaft.

That was/is my biggest concern too. In the picture you can see that there'd still be a little material left around the bushing if the boss was bored out but it looks like it would be kind of thin. I have to do some more measuring, shear a few more and spin a few more yards of wool while I try to decide if boring the hole down to the oil seal to put the bushing as close to the kicker as it can get will handle the pressure from kicking or if it'll just weaken the boss too much.

At this point I'm hoping that the Loctite/Permatex sleeve retaining goo would strengthen the boss by making the steel race more like a permanent part of the casting than just an interference fit steel bushing in a thin-walled aluminum bore.








Here are a few more pictures showing the kicker bore wear, oil seal, and the cosmetic damage from the retaining bolt for the XS850 kicker:



The inner side of the clutch cover. The kicker shaft bore is beginning to show some wear after five years of regular use.






The outer side of the clutch cover. The outer oil seal is still good but the kicker shaft bore is beginning to show some wear after five years of regular use.

Oil seal part#
93102-20108-00 (Ars SD- 20-30-07-HS)
The seal is still available for about $4.00 and is also used on a lot of other bikes including 2011 Yamaha YZ and WR 450F kickers so it's not likely to go away any time soon.







The footrest/muffler support bracket has a small divot where the bolt head for the XS850 kicker lever has been hitting it for five years.

It's cosmetic.




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[Orange4]

Just curious, but why are you kick starting? Save weight with no starter? Running a magneto? Looking all old school while adding a right leg workout to your routine?

[3Phase]

Just curious, but why are you kick starting? Save weight with no starter? Running a magneto? Looking all old school while adding a right leg workout to your routine?

Once upon a time, Yamaha created a very simple starter clutch and then proceeded to wrap the rest of the entire freakin' motorcycle around it. To change a few inexpensive rubber bits and springs when the starter clutch starts to slip means removing the engine and splitting the cases. I do not want to do that again.

Kicking it also takes the load off the alternator and saves some wear and tear on the battery, especially on short trips where the battery may not fully recharge after cranking the engine several times.

And, yes, of course there is the old-school cool factor!

Along with being one of the few that can just kick the engine over even if the battery gets a hair or several low while almost everyone else has to chase their bikes across the parking lot, then jump on and pop the clutch while praying that it starts so they don't have to do it again and/or that it won't get away from them if they slip and fall.
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[TopCatGr58]

Hey Scott,

Okay, I'm assuming that you're going to have to find a machine shop or someone with machine tools to get the clutch/kick starter shaft hole bored out. SO....before you actually bore the cover, see if they can remove some of the thickness of the bearing race/SLEEVE so that it's not so thick!? IT's much harder material than the aluminum case, and so I would think with it's supporting case it can be thinner and still hold up to the stress of the kick starter shaft without bending/warping.....so...it should be able to be thinner which would then allow you to save more case material and its supporting web material by not having to bore such a wide hole!? JAT!

T.C.

[natemoen]

Hey Scott,

Okay, I'm assuming that you're going to have to find a machine shop or someone with machine tools to get the clutch/kick starter shaft hole bored out. SO....before you actually bore the cover, see if they can remove some of the thickness of the bearing race/SLEEVE so that it's not so thick!? IT's much harder material than the aluminum case, and so I would think with it's supporting case it can be thinner and still hold up to the stress of the kick starter shaft without bending/warping.....so...it should be able to be thinner which would then allow you to save more case material and its supporting web material by not having to bore such a wide hole!? JAT!

T.C.

Good thought, in the poor man's non-precise machine shop put the inner race over a screwdriver shaft and lightly touch it to a bench grinder. The race will spin and the grinder will still take material off at a relatively even rate.

[3Phase]

I had to go to the dentist today but I like all of the suggestions I've read!

Thank! You!


I'm using a spare clutch cover for this project so I don't end up walking because I trashed the one that's working now chasing a pipe dream.

The new clutch springs should be here tomorrow and after I put everything back together I'm taking the whole kit-and-kaboodle to a local machine shop to see if it's possible or I'm off in la-la-land again -- like the time I had half the wiring harness torn out so I could fab an ingenious "headlight failure indicator failure indicator" before I came to my senses, put it all back and just bypassed the headlight relay.

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[rdmcguy]

wool gathering??

3phase,
I was wondering what else you might have been doing to those sheep while you were gathering that wool?
Never mind I don't want to know.
I can hear your response now....N-A---AA=AH--THING. lol
Joe