Anyone broken their kickstart shaft like this before ?

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ozzie041974

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Now I know my 71 Commando has good compression (I'm 85kg and have to throw my whole weight on it to kick it through) but this is a bit ridiculous. It actually kicked back at me which probably stressed it I guess. I then kicked again and it started but with a loud cracking noise and a floppy kickstart. Bike was then promptly stopped. On measuring the thickness of the shaft which surrounds the layshaft bush it only measures approx 1.4mm in thickness. Not much when one considers the stress that is exerted time and time again. Pawl pin was also broken into 3 pieces.
Anyone broken their kickstart shaft like this before ?

Anyone broken their kickstart shaft like this before ?

Anyone broken their kickstart shaft like this before ?
 
Man I have never seen one go like that before I broke mine at the pawl about 30 years ago but not like that, maybe just a poor casting???

Ashley
 
Furgenell no! It's rather thin there isn't it? It's a hard/hardened part,maybe that one was too brittle. Some porosity too as ashman said?
 
Steady on Quaterback! Was the bush a slack fit? ..must admit 1.4mm is thin for such a heavy job. I guess some owners have had the original still in good order :?: Back firing ain't going to help. I would get that sorted!..tad of retard.
 
The bush was a snug fit but came out easy with a drift. I can push it back in by hand. I notice when ordering a new shaft it comes complete with the bush. Is it supposed to be a press fit in there or should it be able to spin within the shaft ?
I've got a Mikuni fitted at the moment but just changed the pilot jet. Usually starts first or second kick but this time I missed it. Once that happens with a Mikuni they can be a real pain in the arse. It was the same with a Honda XR400 I had, that had a Mikuni fitted. Anyway this time it decided to kick back at me but wasn't real harsh.
How can you tell it's a pattern shaft ?
 
ozzie041974 said:
I notice when ordering a new shaft it comes complete with the bush. Is it supposed to be a press fit in there or should it be able to spin within the shaft ?
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The bush should be a press fit.

When ordering, insist that you are only sent a genuine Andover Norton item and nothing else, or you could end up getting another pattern item.
 
Sorry L.A.B. Didn't see the photo of the bush come up before I posted last. I'm on really slow internet connection. I'm glad you said Andover Norton because that is where I have ordered from. The thickness of the shaft wall must be the same though regardless but I guess it's the quality that changes.
 
ozzie041974 said:
Sorry L.A.B. Didn't see the photo of the bush come up before I posted last. I'm on really slow internet connection.
Click to expand...

I probably added the photo as you were typing.


ozzie041974 said:
The thickness of the shaft wall must be the same though regardless but I guess it's the quality that changes.
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What is the outside diameter of the bush?

As that bush does not step down in diameter like the genuine item then the metal of the kickstart shaft surrounding it will be very thin-as you have noticed.
 
L.A.B. said:
What is the outside diameter of the bush?

As that bush does not step down in diameter like the genuine item then the metal of the kickstart shaft surrounding it will be very thin-as you have noticed.
Click to expand...

I understand what your saying. Just been down the shed and measured the bush.

Outside Diameter: 25.8mm
Inside Diameter: 17.45mm
Length: 28.35

Be interested to know how this compares to original.
 
ozzie041974 said:
L.A.B. said:
What is the outside diameter of the bush?

As that bush does not step down in diameter like the genuine item then the metal of the kickstart shaft surrounding it will be very thin-as you have noticed.
Click to expand...

I understand what your saying. Just been down the shed and measured the bush.

Outside Diameter: 25.8mm
Inside Diameter: 17.45mm
Length: 28.35

Be interested to know how this compares to original.
Click to expand...

So,

O/D at sholder: 25.05mm
O/D of main section : 22.27mm
Length overall: 28.85mm
Length of main section: 26.0mm
I/D: 17.46mm
 
Thanks L.A.B.
That would mean a difference of 3.53mm between the outside diameter of my pattern bush and the original. As my pattern shaft thickness here was only 1.4mm we can assume an original shaft would have a thickness of approx 3.16mm if my maths is correct. More than double the thickness. Wow that is a huge difference. Moral of the story, DO NOT buy a pattern kickstart shaft.
 
True Norton'rs are always learning more and more about less and less. The two shafts I've tired to get the worn bush out of were so tight I ended up grinding a slot to break up and remove and easier on a hick than creating or sourcing a puller. The exploded parts photo is most fascinating force failure I've seen displayed in that area. Might take a good light and lens and hunt for slight discoloration in cracked surface that may reveal a slight nick in surface that let oxygen in to corrode along metal grain lines till its stress riser suddenly completed its path. I didn't know they could go bad that bad as only seen them with cracks showing or the splines chewed up. I have a replacement with Peel's wham-bam-thankyou mam Hi CR 920 in mind but only because pensive of the splines in old one. Here's they are side my side - forgot w/o hunting invoice who sold it, but note the finish difference and the thickness of the milled ridge area. Can anyone ID this beauty as good to the bone or only just skin deep pretty? Is there a measure I should do to to help with ID of variations off the Anover item?

Anyone broken their kickstart shaft like this before ?
 
The older one looks like a good Radi is machined in the corners?
hobot said:
True Norton'rs are always learning more and more about less and less. The two shafts I've tired to get the worn bush out of were so tight I ended up grinding a slot to break up and remove and easier on a hick than creating or sourcing a puller. The exploded parts photo is most fascinating force failure I've seen displayed in that area. Might take a good light and lens and hunt for slight discoloration in cracked surface that may reveal a slight nick in surface that let oxygen in to corrode along metal grain lines till its stress riser suddenly completed its path. I didn't know they could go bad that bad as only seen them with cracks showing or the splines chewed up. I have a replacement with Peel's wham-bam-thankyou mam Hi CR 920 in mind but only because pensive of the splines in old one. Here's they are side my side - forgot w/o hunting invoice who sold it, but note the finish difference and the thickness of the milled ridge area. Can anyone ID this beauty as good to the bone or only just skin deep pretty? Is there a measure I should do to to help with ID of variations off the Anover item?

Anyone broken their kickstart shaft like this before ?
Click to expand...
 
The older one looks like a good Radi is machined in the corners?
Click to expand...

Hm, John, might well be so, glad you noticed in time for machinist to touch up if if the new one can stand it. I will have a closer look see as the chrome finish dazzled me too much prior. Kind of interesting that there is big enough market that pattern parts are worth bothering with.
 
Crikey .

ratre but not unkmown . Large workboots and 15 stone rider , and full off muscle . Mightve seen one once & a picture . So youre No 3 . 8)
 
Ozzie, do you know where your dodgy one came from ? The person selling those deserves to be hounded out of business. How much did they save by using a straight bush instead of shouldered ?

This shaft would fit any AMC box so this may not be a specific Commando counterfeit problem. They could just as easily have been made for Matchless singles and not be anything to do with our usual suppliers at all.
 
79x100 said:
The person selling those deserves to be hounded out of business. How much did they save by using a straight bush instead of shouldered ?
Click to expand...

It's almost as if they were intended to last for a short time before they break? If it breaks then you have to buy another.
 
Matt Spencer said:
Crikey .

ratre but not unkmown . Large workboots and 15 stone rider , and full off muscle . Mightve seen one once & a picture . So youre No 3 . 8)
Click to expand...

The year was 1972. I rode my brand spankin new commando to a remote area to visit a family of back woods loggers. The 18 year old son was every inch a man, I think they started him setting chokers and pullin riggin at age 12 and he was built like a gorilla. His enthusiasm over my new commando was ecstatic and he winced and twisted like a kid at christmas for me to let him take it for a ride. I gave in as having known him for several years I had always thought of him as older and more mature than myself 2 or 3 years his senior. I don't think he ever had a childhood, he was a rock solid individual who I'd never seen act this excited. He proceeded to stall it right off the get go and I watched as he raised his foot 10" above the kick lever and come down on it as though he was drop kicking a stubborn choker bell. I quickly intervened showing him how to do it right. An hour or so after he disappeared down the road I walked 2 - 3 miles up to find him in the same situation as your kick start was in. After he stalled it up there he proceeded to use the drop kick method of starting the bike till he broke the shaft and cracked the inner case and I don't remember what else. The lever was jammed in the downward position and wouldn't budge. So yeah, you can shock load the components of even the stock kick start assembly. After that episode I learned to bring the pistons up to TDC and slowly apply weight to start every thing in motion slowly, then accelerate your kicking motion through the stroke.

Good catch on the after market parts LAB!!!
 
The year was 1972. I rode my brand spankin new commando to a remote area to visit a family of back woods loggers. The 18 year old son was every inch a man, I think they started him setting chokers and pullin riggin at age 12 and he was built like a gorilla. His enthusiasm over my new commando was ecstatic and he winced and twisted like a kid at christmas for me to let him take it for a ride. I gave in as having known him for several years I had always thought of him as older and more mature than myself 2 or 3 years his senior. I don't think he ever had a childhood, he was a rock solid individual who I'd never seen act this excited. He proceeded to stall it right off the get go and I watched as he raised his foot 10" above the kick lever and come down on it as though he was drop kicking a stubborn choker bell. I quickly intervened showing him how to do it right. An hour or so after he disappeared down the road I walked 2 - 3 miles up to find him in the same situation as your kick start was in. After he stalled it up there he proceeded to use the drop kick method of starting the bike till he broke the shaft and cracked the inner case and I don't remember what else. The lever was jammed in the downward position and wouldn't budge. So yeah, you can shock load the components of even the stock kick start assembly. After that episode I learned to bring the pistons up to TDC and slowly apply weight to start every thing in motion slowly, then accelerate your kicking motion through the stroke.

Good catch on the after market parts LAB!!!
Click to expand...

Good on you Rip for giving in too life's desires and making a lasting memory for all concerned. I thought Matt was just teasing us about this before inferior, non factory, parts hit the market. Best thing I did to preserve my kickers was get bike to routine one kick starts state, so factory only made it to stand those loads on their singles it seems.
 
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