Author Topic: Kickstart cotter pin  (Read 7086 times)

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Phil C

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Kickstart cotter pin
« on: 19 January, 2018, 13:34:34 »
Went to start my new 1965 B40 this morning. Gave it half a dozen or so kicks - it wouldn't start and then sometimes wouldn't turn over - appeared stuck solid. The compression lever didn't appear to make any difference. The kickstart then stuck at or near the bottom of its travel - maybe turned on the shaft? I wondered if the cotter pin nut was loose, tried to tighten it but the threads are stripped on the pin, so I need to replace that. The kickstart is stuck at the bottom of its swing, next to the exhaust. So I'm thinking I need to get the cotter pin out, turn the kickstart lever on its shaft so that its at the top again, refit the pin, and try to kick it over again. Trouble is, I'm struggling to get the pin out. Hitting with a hammer (slightly awkward because its close to the exhaust) isn't moving it, just peening over, and possibly bending, the pin. Any ideas please? If I bought a heat gun would that work (and be safe?)

Also, any ideas why it wouldn't kick over?

Phil C

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Re: Kickstart cotter pin
« Reply #1 on: 19 January, 2018, 15:24:02 »
I think I probably stripped the threads because I should have tightened the pin by hammer from the other end, and then just nipped up the nut. Anyway, it gets worse! The threaded part of the pin bent over when I hit it, and then when I tried to straighten it it broke off, below the level of the hole in the kickstart lever (hopefully I have attached a photo to this)  So now to hit the pin, in order to try to get it out, I guess I need a parallel punch or a drift of some kind to poke into the hole and then hit with a hammer. But given the ease with which the threaded part of the pin bent and broke, I'm a bit worried that hitting it more is going to peen over the pin in the hole to the extent that it's too fat to get through the hole. This is made even more tricky by the fact that I'm having to hit upwards, and the exhaust is a bit in the way so that I'm having to come at it from an angle (increasing the chances of bending the pin or peening it over). I guess I could take the exhaust off, but even then it would still be a bit difficult trying to hit uphill (see photo attached.) Any ideas/advice would be much appreciated! Being new to all this, I expected problems! Thanks in advance for any advice.

AWJDThumper

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Re: Kickstart cotter pin
« Reply #2 on: 19 January, 2018, 17:26:10 »
The only way to remove it is with a parallel punch - however, you need to use one with roughly the same dia as the cotter pin to avoid the punch simply expanding the pin. If there isn't enough room then it might be best to remove the downpipe. If you're right-handed like me then I would almost be tempted to lean of the seat to get the right angle to hit the end of the punch.

Phil C

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Re: Kickstart cotter pin
« Reply #3 on: 19 January, 2018, 17:42:11 »
Thanks. Given that the kickstart turned on its shaft when I tried to kick it over, might it tap off the shaft if I give it a knock with a hammer and drift without removing the pin? If it did then removing the cotter pin afterwards might then be not so difficult.

What about the heat gun idea? Would it help, and would it be safe?

Dean Southall

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Re: Kickstart cotter pin
« Reply #4 on: 19 January, 2018, 17:56:46 »
If you've got a mig welder you could try welding a bar to the end of the cotter pin to give yourself some purchase.
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Phil C

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Re: Kickstart cotter pin
« Reply #5 on: 19 January, 2018, 18:09:08 »
No, I haven't. Also, I wonder how the kickstart could turn on the shaft. Is there not a flat on the shaft that locates with the flat on the cotter pin?

AWJDThumper

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Re: Kickstart cotter pin
« Reply #6 on: 19 January, 2018, 18:47:42 »
You have to use the correct cotter pin wedge profile - I've come across a lot that are incorrect. You can then find the cotter pin is a very tight fit in the kickstart lever but doesn't fit the cut-out in the shaft - hence the lever can move. All you need to do is hit the end of the cotter pin hard enough and it will come out - but make sure you use the right sized punch and direct the force along the axis of the cotter pin.

Phil C

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Re: Kickstart cotter pin
« Reply #7 on: 19 January, 2018, 19:44:42 »
Would a heat gun help? Or is it to close to oil/oil seal? I'd need to buy one. Obviously I'd try without first.

Phil C

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Re: Kickstart cotter pin
« Reply #8 on: 19 January, 2018, 19:49:29 »
To answer my own stupid question, having taken a minute to think, there's no oil nearby, so a heat gun should be safe enough, but might not make any difference to getting the pin out. Is that right?

OVERTHEHILL

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Re: Kickstart cotter pin
« Reply #9 on: 19 January, 2018, 22:19:31 »
Forget the heat gun, as someone has already said a parallel punch and a smart blow with a hammer.  A fairly heavy hammer if you have one or can borrow one.
charlie

Phil C

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Re: Kickstart cotter pin
« Reply #10 on: 19 January, 2018, 22:49:02 »
Okay, thanks. I'll get a parallel punch and try again with the club hammer - maybe take the exhaust off first to get a good straight blow.

AWJDThumper

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Re: Kickstart cotter pin
« Reply #11 on: 20 January, 2018, 09:15:51 »
It is not advisable to use a club hammer to remove the cotter pin - a smaller hammer and sharp blow should be sufficient. Main challenge is to sort out the geometry for delivering the hammer blow. If you've got a left-handed friend, that would make it easier ;D

Phil C

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Re: Kickstart cotter pin
« Reply #12 on: 20 January, 2018, 09:45:59 »
Okay thanks. No left-handed friends around, I'm afraid. I thought for a moment you were going to recommend a left-handed hammer ( bit like a long weight, etc.) But seriously, it's a tricky angle, and of course the surface of the pin I'll be hitting against, which is where it broke off, is uneven. Anyway, I'll see if I can find a parallel punch, take the silencer off, and give it a sharp tap. I've put WD40 on. But it felt very stuck when I was trying to get it out the other day. How I'd love it to pop out, and there be no damage to the shaft. At the moment I can easily move the kickstart both ways about, say, an eigth of a turn with no resistance - so I guess there's something amiss down there - I'm hoping it's just the pin and not the shaft aswell. Of course not knowing anything about kickstart mechanisms doesn't help!

JulianS

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Re: Kickstart cotter pin
« Reply #13 on: 20 January, 2018, 09:53:27 »
The pin is probably a soft one - the hard edge of the shaft digs into the soft material and the ultimate result it you cant tighten it, it just rocks. If the edge has dug in it makes it  harder to drift it out and you might need to carefully drill.

Source a good quality cotter when refitting, they come with different degrees of machined flats to suit different shafts/levers. I got some very good and hard ones form Dave Flintoff the Gold Star man.

AWJDThumper

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Re: Kickstart cotter pin
« Reply #14 on: 20 January, 2018, 11:36:09 »
You don't need to worry about the shaft - it's hardened steel. As Julian says, the cotter pin is normally mild steel and, in your case, is just wedged into the RHS of the kickstart lever. You just need to hammer it out with a punch just small enough to go through the hole in the LHS of the lever. If I was doing it, I would probably lean over the saddle with the silencer off to achieve the correct geometry for applying the hammer blows. Alternatively, lean the bike over carefully on to its left side to make it easier as long as fuel/oil doesn't leak out!