BSA Owners' Club Forum

The BSA Workshop => Singles => Topic started by: Phil C on 19 January, 2018, 13:34:34

Title: Kickstart cotter pin
Post by: Phil C 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?
Title: Re: Kickstart cotter pin
Post by: Phil C 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.
Title: Re: Kickstart cotter pin
Post by: AWJDThumper 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.
Title: Re: Kickstart cotter pin
Post by: Phil C 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?
Title: Re: Kickstart cotter pin
Post by: DEAN SOUTHALL 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.
Title: Re: Kickstart cotter pin
Post by: Phil C 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?
Title: Re: Kickstart cotter pin
Post by: AWJDThumper 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.
Title: Re: Kickstart cotter pin
Post by: Phil C 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.
Title: Re: Kickstart cotter pin
Post by: Phil C 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?
Title: Re: Kickstart cotter pin
Post by: OVERTHEHILL 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
Title: Re: Kickstart cotter pin
Post by: Phil C 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.
Title: Re: Kickstart cotter pin
Post by: AWJDThumper 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
Title: Re: Kickstart cotter pin
Post by: Phil C 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!
Title: Re: Kickstart cotter pin
Post by: JulianS 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.
Title: Re: Kickstart cotter pin
Post by: AWJDThumper 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!
Title: Re: Kickstart cotter pin
Post by: JOHN KAY on 20 January, 2018, 16:20:23
HI PHIL

JUST AN IDEA NOT SAYING THIS WILL WORK BECAUSE THE PIN MAY BE TOO TIGHT BUT YOU COULD TRY
USING A G CLAMP AND SOME KIND OF NUT AS A SPACER AND SHORT BOLT AS A PUSHER AND PUSH IT OUT
BY SCREWING UP THE G CLAMP . THIS IS ALL IN THEORY OF COURSE AS THE G CLAMP MIGHT BREAK >
REGARDS JOHNBOY .
Title: Re: Kickstart cotter pin
Post by: Phil C on 20 January, 2018, 18:11:18
I like the theory - thanks, Johnboy. I'll try that if the hammer doesn't work. Although I wonder whether, in practice, the uneven surfaces (of the broken pin and the contoured kickstart) might make it too wobbly to get enough pressure in the right direction. One way to find out.

Can anyone suggest why the it jammed absolutely solid when I was trying to kickstart the engine? Not just very stiff, it felt absolutely solid, which I guess is why the kickstart/cotter pin arrangement slipped. I pulled in the valve lifter lever, but that seemed to make no difference whatsoever.

Phil.
Title: Re: Kickstart cotter pin
Post by: BEESY on 20 January, 2018, 18:56:10
I had a similar problem with a bantam. It turned out to be a bent return spring.

As the kick start lever went down the tension in the bent spring would push the quadrant out of alignment with the clutch basket. When the pressure taken off kuckstart lever and spring tried to unwind the teeth onquadrant and clutch jammed up.

Try putting bike in gear and gently rock it backwards to see if it frees it up.
Title: Re: Kickstart cotter pin
Post by: AWJDThumper on 20 January, 2018, 19:51:05
Depending on which year your B40 is, there were two different types of kickstart mechanism used. The later ones used a quadrant and rachet pinion combination. With these types, it was not uncommon for the first teeth on the quadrant to engage the rachet pinion to get chewed up which could then stop the kickstart from rotating. The earlier B40's used a different mechanism and were less prone to jam. If your's is a later B40 and you have this jamming problem then it's likely you'll need to replace the quadrant which is what the kickstart is attached to via its shaft.
Title: Re: Kickstart cotter pin
Post by: Phil C on 20 January, 2018, 20:46:48
Mine's 1965. Quadrant and ratchet?  If so, then I guess first take off the cover and have a look at the teeth, but if there's damage, as you suggest, then would it be a difficult job? Feasible for a novice, or not?
Title: Re: Kickstart cotter pin
Post by: JulianS on 20 January, 2018, 21:03:28
If engine is B40F number then its a quadrant. Plain B40 then its ratchet.
Title: Re: Kickstart cotter pin
Post by: Phil C on 20 January, 2018, 21:31:26
Yes, B40F - thanks. Anyway, first things first: the broken, jammed cotter pin.
Title: Re: Kickstart cotter pin
Post by: Phil C on 20 January, 2018, 22:30:07
Oh yes, as I was saying, if I did need to replace the quadrant, is that feasible for a novice?   Phil.
Title: Re: Kickstart cotter pin
Post by: AWJDThumper on 21 January, 2018, 09:09:30
Since you need to get at the quadrant, all you need to do after removing the gear change lever is to undo all the screws in the outer timing cover (RH cover) and pull it off. The quadrant will pull out with the cover and it will then be a lot easier to remove the cotter pin on the bench. It's very easy to put it all back again. You simply insert the replacement quadrant with spring into the side of the gearbox and then put the timing cover back on - a 30 minute job :)
Title: Re: Kickstart cotter pin
Post by: AWJDThumper on 21 January, 2018, 09:32:37
Sorry - brain wasn't quite in gear and for some reason I was thinking distributor model. Unfortunately, you will probably need to remove the contact breaker points plate as well - I think the screw in posts that hold the plate in place screw into the inner timing cover and so have to be removed before the outer cover can be taken off. It's best to precisely mark the position of the plate relative to the outer cover so that you can put it back without having to check the ignition timing.
Title: Re: Kickstart cotter pin
Post by: Phil C on 21 January, 2018, 10:32:34
Thanks very much for this. Of course I don't know yet whether the quadrant is damaged. If I can get the cotter pin out with the cover etc still on the bike, then I'll see if the kickstart lever jams again, and if it does then I'll take the cover off and have a look at the quadrant etc. But from what you say above, it appears that if I can't get the pin out with the cover still in place then I could take the cover off, complete with kickstart mechanism, and try to remove the pin on the bench. So the next thing to do now is still to try to hammer the pin out - I've ordered a set of parallel punches online and am waiting for them to arrive. Pathetic, isn't it, haven't even got any punches. I'm working in a very limited environment - small shed, bench and vice, that's about it. I must say I'm finding this forum very encouraging.
Title: Re: Kickstart cotter pin
Post by: Phil C on 21 January, 2018, 10:38:15
By the way, Johnboy, I haven't forgotten your g-clamp idea!
Title: Re: Kickstart cotter pin
Post by: AWJDThumper on 21 January, 2018, 10:42:51
If the jamming is due to a damaged quadrant, you should find that the kickstart lever will move freely the first few degrees before the teeth on the quadrant jam with those on the ratchet pinion - it will be like hitting an immovable object with the lever. I assume that all the gears normally engage properly and the engine turns over ok?

If you do need to take off the outer cover, I've just checked and the contact breaker plate should come away with the cover - there's no need to disturb the plate other than to disconnect the wire that goes to the points.
Title: Re: Kickstart cotter pin
Post by: Mike Farmer on 21 January, 2018, 11:35:30
 :)
Do you have a bench??? If so load your bike with the wheels onto the edge of the bench with the offending kick start out to the side. Fix bike firmly in place.

This will give you all the space you need to enable you to get at it easily to drive out the pin.

If you get a similar problem in future, leave the nut on the pin and only undo it about 1/16th, and (once it moves undo it another 1/16th and repeat) this way you will have a much larger strike area when you hit it and you will be less likely to bend the threaded part. It will still probably kill the pin but that's no problem.

Mike 8) 8)
Title: Re: Kickstart cotter pin
Post by: Phil C on 23 January, 2018, 16:36:03
Hello everyone, Some of you might remember this from a few days ago. Anyway, here's the latest. My punches arrived this morning, so off I went to my little shed to try to get the broken cotter pin out. I took the exhaust off, got my daughter to lean the bike over, and started tapping. It took a good few hits, but eventually, just as people on this forum said it would, it came out. I was interested to see the damage (see photos attached of old pin, new pin, and spindle.) This looks very much as described in Rupert Ration, p.107, and I wonder if the problem came about because of the pin coming loose over time. Anyway, I now have a choice: 1. I could refit the kickstart lever with the new pin, and see what happens, or 2. I could take the outer cover off and check the teeth on the quadrant. When the problem started, the kickstart lever seemed to hit solid resistance sometimes when I tried to kick the engine over, and some people advised that it could be due to damaged teeth. What do you think regarding these two options?
Title: Re: Kickstart cotter pin
Post by: AWJDThumper on 23 January, 2018, 17:21:09
Put the new pin in and try the kickstart. If the gearbox is otherwise ok but the kickstart appears to jam when the quadrant teeth start to engage with the ratchet pinion then it's likely the quadrant is damaged. A new pin should come out fairly easily.
Title: Re: Kickstart cotter pin
Post by: Phil C on 24 January, 2018, 16:33:20
Fitted the new pin, kicked over about six or seven times before it started - kickstart lever seemed to jam a bit at one point but then was okay. I guess I'll see how it goes. Anyway, having made a big deal out of a very small job, I'll just say thanks to everyone for their advice. Great fun!