kick start comes loose

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Hi

I'm having trouble keeping my kickstart tight on the shaft...I was thinking that I should Loctite the bolt, but I wonder if it would help to put Loctite onto the splines?

Or does anybody have any other ideas?

Lastly, is there a torque wrench setting for the bolt? I don't want to overtighten it.

Thanks

Alex
 

L.A.B.

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I'm not sure using Loctite on the splines will help? I had the same problem with my Mk III kickstart and no matter how hard I tightened the bolt, within a few kicks it would be loose again.
I think the splines of both parts were slightly worn, and even tightening the 3/8" bolt as much as I dare, the lever still wasn't clamping itself around the shaft with much force, so kept coming loose, and the bolt could have been stretching?

In the end I drilled and tapped the bolt hole oversize, and by using a larger diameter bolt I was able to get it much tighter, and that cured the problem, as it's never come loose again.
I think I had to open the hole out slightly off-centre away from the splines, so that the larger diameter bolt would not hit the shaft as it was screwed in?
 
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I found these ideas on this site and used the first one.
I cured the same problem by putting three hacksaw cuts around the inside of the kick lever where it clamps on the shaft. about 1/16" deep at 3 oclock, 6 oclock, and nine oclock, (with the clamp bolt slot at 12 oclock )
This has allowed the clamp to close tighter around the shaft and has never come loose since I did it.
Another thread on this site suggested grinding a couple of splines off of the shaft where the bolt tightens the clamp on, to give the clamp room to close around and tighten on the shaft.
 

Ron L

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Another thread on this site suggested grinding a couple of splines off of the shaft

Actually I think that was my suggestion, but the idea is to grind a couple splines off the kickstart arm, not the shaft. The idea is this allows more movement at the slit. If the slit is closing completely and the arm is still loose, then you can widen the slit with a cut off wheel. Unfortunately both of these will remove chrome and will allow rusting unless painted or replated.
 
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Rule one; Don't use a stainless steel bolt.

Rule two; Do use a high tensile steel bolt.

Rule three; Tighten the blighter til it squeals, your tongue sticks out and your eyes squint.

Simple really.

Cash
 
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thanks for the replies.

I'll probably try them all until I'm sure the problem is solved, starting with removing the stainless steel bolt...

I'm curious to know why stainless steel bevaes differently to non-stainless in this application

Thanks

Alex
 

L.A.B.

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old grey biker said:
I'm curious to know why stainless steel bevaes differently to non-stainless in this application

Although there are many different alloys of "stainless steel" it doesn't generally have a particularly high tensile strength. The type used for normal decorative fasteners (304 & 316) has a tensile strength not much above mild steel.
 
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Cash, (or anyone else..)

Can you recommend a part number or description for an appropriate high-tensile bolt. ie: Chevy S10 brake caliper mount bolt.

The guys a parts counters usually look at me blankly when I say things like 2" UNF high tensile bolt for my 1970 Norton kick lever please....
 

Ron L

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It's 3/8" X 26tpi X 1 1/2" so unless you have access to CEI thread bolts you will probably need to get it from a Norton parts dealer.
 
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So, after cutting slots and grinding off splines and chucking the stainless steel bolt in the bin, the kickstart stayed tight for about six kicks :(

Maybe I'm just not tightening the bolt enough????

does anybody have a recommended torque setting for this bolt?

Thanks
 

MichaelB

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cash said:
Rule three; Tighten the blighter til it squeals, your tongue sticks out and your eyes squint.


Sounds about right.
Check and repeat.
 
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Mine kept working loose too, even though it's a newer Mk3 arm and new shaft. The new arm comes with the splines machined away near the slit BTW.

I removed the arm, cleaned the splines on arm and shaft, and tightened the bolt good and tight as suggested above.

It's been staying tight.

Debby
 

L.A.B.

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Ron L said:
It's 3/8" X 26tpi X 1 1/2" so unless you have access to CEI thread bolts you will probably need to get it from a Norton parts dealer.

I think that 3/8" bolt (06-0599) is UNF - 24 tpi, - and not 26 tpi Cycle thread. The one in my kickstart was 3/8" UNF (before I drilled it oversize) and the spare lever with bolt I have on my spares shelf is also UNF.

It also shows up as UNF on the Norvil list: http://www.norvilmotorcycle.co.uk/gearbox.htm

"060599ASS BOLT & WASHER - KICKSTART - 3/8" x 1 1/2" UNF"

The very useful Stainless Fasteners list would appear to be wrong as that lists it as Cycle thread.
 
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