Went to War with Kickstart Clamp....

Tornado

Tornado

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After having a repeated wobble develop in my kicker to shaft clamp, went to war on it...The clamp splines on my kicker are in tough shape...multiple "levels" across the length of the splines, persumably from previous attempts to tighten down and it working loose, not being square to the shaft etc

Followed procedure as per several threads on the forum...filing/grinding off several splines nearest the clamp split & grinding the split gap wider. All seemed good after multiple starts today...no more wobbling and holding well. War Won!
But I got greedy...the kicker was not oriented where I wanted it...bit too far forward such that it was not a good position for my foot on the footpeg. So after a thorough ride today, pulled it off again, rotated aft on the shaft to where foot was happy, and began re-torquing the tired old original bolt...SNAP. broke off just after beginning of threaded section and now the rest of thread is stuck deep in the clamp bolt hole. Got the kicker off the splines though, so the battle now continues to remove the broken section and source a new bolt.
Mentions of hardened bolts abound...what are the thread and bolt dimensions I need?
 
My original kicker use to stay tight but some scum bag stole it, this was in the late 70s when my GB blew the layshaft bearing and was in pieces under my house, took me 4 months of push starting my Norton before I was able to chase down a new kicker, the new one kept going lose and had to tighten the bolt up every 3 or 4 days how I fixed it was cut the gap wider but the bolt couldn't thread right through so I drilled the end of the kicker so a longer KS bolt could threat right through, I would tighten it right up then put a nyloc nut on the end of the bolt and tighten it up as well, never had a problem with the kicker coming lose after doing that.
But I have replaced that kicker now with the folding T160 kicker and it stay tight, has never come lose on the spline, but sometimes I got to give the folding bolt a slight tighten.
 
Tornado said:
After having a repeated wobble develop in my kicker to shaft clamp, went to war on it...The clamp splines on my kicker are in tough shape...multiple "levels" across the length of the splines, persumably from previous attempts to tighten down and it working loose, not being square to the shaft etc

Followed procedure as per several threads on the forum...filing/grinding off several splines nearest the clamp split & grinding the split gap wider. All seemed good after multiple starts today...no more wobbling and holding well. War Won!
But I got greedy...the kicker was not oriented where I wanted it...bit too far forward such that it was not a good position for my foot on the footpeg. So after a thorough ride today, pulled it off again, rotated aft on the shaft to where foot was happy, and began re-torquing the tired old original bolt...SNAP. broke off just after beginning of threaded section and now the rest of thread is stuck deep in the clamp bolt hole. Got the kicker off the splines though, so the battle now continues to remove the broken section and source a new bolt.
Mentions of hardened bolts abound...what are the thread and bolt dimensions I need?
Click to expand...
Unless you know it's original, that is probably an unanswerable question. I've seen UNF, Metric, and BSC. If you get it out, head to the hardware store and see if anything fits. If not, then it's probably BSC.

You could drill it out and use a bolt and nut.
 
Check the splines on the KS shaft. They are most likely as chewed as the KS itself. No matter how often you tighten it up it will loosen and rattle very soon. Then the KS splines finally tear off, leaving you in a bad spot. Best to spend the necessary $$$ and install a new shaft and MK3 KS lever. This is, unfortunately, about $450 these days if you do your own work but once done and tightened a couple of times it will not come loose again. No more aggravation.
 
Shaft splines look ok. I have a friend tgat owes me some favours and he has a mk2 kicker I can claim in pretty new condition as it was on his Mk3 up until tecently, not being used for starting duty. He now has the proper mk3 kicker.
 
L.A.B. said:
If original then it should be 3/8" x 1 1/2" UNF preferably high tensile.
Click to expand...
It did take a 9/16 SAE socket quite well and not a Whitworth, so most likely UNF. Planning to habe a go with Easyouts when I can find them...
 
Tornado said:
It did take a 9/16 SAE socket quite well and not a Whitworth, so most likely UNF. Planning to habe a go with Easyouts when I can find them...
Click to expand...
I would try a left-hand drill bit from the good end of the bolt. It will most likely back it out, but if not will drill the hole needed for the easyout.
 
Tornado said:
It did take a 9/16 SAE socket quite well and not a Whitworth, so most likely UNF. Planning to habe a go with Easyouts when I can find them...
Click to expand...
Easyouts are not my favourite tool
In fact they are the last I reach for,if you break an easyout in there it's a whole new game involving a spark eroder
If it were mine I'd put a washer over the hole and tig weld the broken bolt to the washer
Then weld a nut to the washer
The expansion from the heat of welding usually breaks the hold on the thread
Then before it completely cools wind it out
If the weld breaks try it again
If it continually breaks drill it out accurately and pull the thread out like a spring
 
marshg246 said:
I would try a left-hand drill bit from the good end of the bolt. It will most likely back it out, but if not will drill the hole needed for the easyout.
Click to expand...
I think if drilled from the outside of the clamp hole into the unbroken end of the remaining threaded section, a RH drill will twist it clockwise from the unbroken end, which means a counter-clockwise rotation from the broken end, correct?
 
OK, got a drill through remnant section from outside end. Found my screw extractor set (not strictly an easyout type). Gave the extractor a few taps with ballpeen. Attached the powerdrill in slow reverse and the remnant backed out A.OK. Even found a stainless 3/8 UNF in my old sailing spares kit of suitable length. Kicker back on the bike and no signs of wobble...but will search for a harder material bolt or order the stock if needed.
 
Tornado said:
OK, got a drill through remnant section from outside end. Found my screw extractor set (not strictly an easyout type). Gave the extractor a few taps with ballpeen. Attached the powerdrill in slow reverse and the remnant backed out A.OK. Even found a stainless 3/8 UNF in my old sailing spares kit of suitable length. Kicker back on the bike and no signs of wobble...but will search for a harder material bolt or order the stock if needed.
Click to expand...
Stainless boat hardware is cheddar cheese soft.

Remove 5 splines on each side of the split.

Get a grade 8 bolt. Available at any REAL hardware store. (not paint & wallpaper store)
 
Last edited:
Agreed on the grade 8 bolt. And given the compromised condition of the internal splines etc, tighten it up with a 3 foot breaker bar.
 
The Kickstart on our Atlas failed about 20 years ago .i replaced it with an orriginal non folding rusty Bracebridge St one from an old 99 . its still in use and not wobbly . Proper steel. Unless a free sample appears its staying.
 
norton bob said:
The Kickstart on our Atlas failed about 20 years ago .i replaced it with an orriginal non folding rusty Bracebridge St one from an old 99 . its still in use and not wobbly . Proper steel. Unless a free sample appears its staying.
Click to expand...
The atlas/dommie type kickstart lever is a better design than the commando one I think it's been discussed on here before
It's because the shaft is 180° from the gap in the spline
And the commando lever is 90°
The atlas type clamps better
 

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