CNW e start conversion, sprag failures

Deets55 said:
Still not sure I would lube a sprag except in a dry primary, but I bet this stuff would work great in the speedo gearbox. That Mobilux is available in the US too.
Thanks for posting that.
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Deets,
I have used Jim Comstock’s tip on using engine assembly lube in my speedo gearbox with good results.Just don’t overfill.
Mike
 
YING said:
Deets,
I have used Jim Comstock’s tip on using engine assembly lube in my speedo gearbox with good results.Just don’t overfill.
Mike
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Mike,
Been using that John Deere Corn Head grease with very good results, was just thinking out loud about that Mobile grease
Pete
 
Deets55 said:
Mike,
Been using that John Deere Corn Head grease with very good results, was just thinking out loud about that Mobile grease
Pete
Click to expand...
Deets,
What is CornHead grease?Is it a liquid? I have never heard of such a product and how often do you use it.
Thanks,Mike
 
While we are on assembly lube... What about injecting it into the swing arm?? or STP?
I would like to find something that won't drip out so fast!!
Dennis
 
robs ss said:
Thanks Glen
Do you happen to know if that also fits a standard Mk3 as well?
If so, I would buy one for a riding friend.
Cheers
Rob
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Yes it should. My bike is pretty much standard. I'm reasonably certain that the starter parts, other than the sprag itself, are all original items.
The fellow I bought the bike from was the original owner. He gave me receipts for all work done on the bike while he owned it. The only changes to the starter system were a mod to 4 brush starter and heavy cables added.

Glen
 
dobba99 said:
After my post about modifying the roller cam sprags to fit the Mk3 i was asked if they would fit the CNW e start conversion kit (as apparently they use the same size of sprag i was told)
Click to expand...

dobba, what was the answer, do your upgraded sprags fit in the cNw starter kit ?
 
worntorn said:
Yes it should. My bike is pretty much standard. I'm reasonably certain that the starter parts, other than the sprag itself, are all original items.
The fellow I bought the bike from was the original owner. He gave me receipts for all work done on the bike while he owned it. The only changes to the starter system were a mod to 4 brush starter and heavy cables added.

Glen
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I know a MK3 owner that never knew there was a any issues with the electric start
He's owned the bike around 35 or more years and it's always been on the button
The previous owner had fitted heavier leads and solenoid but that was all
 
Fast Eddie said:
dobba, what was the answer, do your upgraded sprags fit in the cNw starter kit ?
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Morning Nigel
When i have confirmation that the roller cam sprag will fit in a cnw kit i will let you know, I'm told that they use the same size sprag as the Mk3 and now that HNW are supplying them (and they supply the cnw kit) i,m sure it wont be long before one gets fitted.
Doesn't get around the fact that the sprag (in the cnw kit) is operating outside its recommended useage. Like i said previously, treat the sprag as a service item until the operation of the sprag is corrected.
Cnw sprag failures, answer, quite a few. If you factor in the reluctance of owners to admit that after having spent £2500 plus fitting a kit that still has sprag problems there are probably quite a few more.
Regards
Peter
 
baz said:
I know a MK3 owner that never knew there was a any issues with the electric start
He's owned the bike around 35 or more years and it's always been on the button
The previous owner had fitted heavier leads and solenoid but that was all
Click to expand...
I wonder what the previous owner did to the starter motor to stop the rotor wearing into the drive end plate? The two pole prestolite has a built in fault that will gradually degrade its performance till it gets to the point that the starter won't start the engine.
 
What are the symptoms of a sprag failure?

Is it a gradual kinda thing with some warning over time, or a sudden / catastrophic failure?

I’ve never had the pleasure, thus far at least !

Reason for asking is I ain’t got no kick start fitted …
 
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dobba99 said:
I wonder what the previous owner did to the starter motor to stop the rotor wearing into the drive end plate? The two pole prestolite has a built in fault that will gradually degrade its performance till it gets to the point that the starter won't start the engine.
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Next time I see him I'll ask if the starter has ever had any work
I didn't think it had but I may be wrong
 
Fast Eddie said:
What are the symptoms of a sprag failure?

Is it a gradual kinda thing with some warning over time, or a sudden / catastrophic failure?

I’ve never had the pleasure, thus far at least !

Reason for asking is I ain’t got no kick start fitted …
Click to expand...
Afternoon Nigel
I'll ask the chap who i know has a cnw kit fitted and ask him what the failure mode was, i would put money on the sprag not engaging.
 
Fast Eddie said:
What are the symptoms of a sprag failure?

Is it a gradual kinda thing with some warning over time, or a sudden / catastrophic failure?

I’ve never had the pleasure, thus far at least !

Reason for asking is I ain’t got no kick start fitted …
Click to expand...
Nigel
This was Trevors answer:-
Not engaging. Tries to hook up but can't. Failure was progressive- the odd attempted start would spin, give it a moment and try again and it'd fire up. Got worse until all it did was spin without turning the engine.
 
dobba99 said:
Nigel
This was Trevors answer:-
Not engaging. Tries to hook up but can't. Failure was progressive- the odd attempted start would spin, give it a moment and try again and it'd fire up. Got worse until all it did was spin without turning the engine.
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That’s great info, thanks Peter.

I can live with the risk of a progressive failure (especially given the reliability to date) more that the risk of a sudden / catastrophic one.
 
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Fast Eddie said:
What are the symptoms of a sprag failure?

Is it a gradual kinda thing with some warning over time, or a sudden / catastrophic failure?

I’ve never had the pleasure, thus far at least !

Reason for asking is I ain’t got no kick start fitted …
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Unfortunately mine just went away instantly.

Pressed the button one day and it just spun without turning the motor. I keep an RGM folding kick-start on my bike.
 
Café au Lait said:
Mine fitted 2021 or about 9k miles ago, no issues and I’ve recently inspected it twice as documented in another thread
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Well bugger me sideways, I now regret making this post, that’ll teach me😂

On day 3 of my 5 day marathon to Pescara, Italy having already lost one companion 2 days earlier on his non starting ‘23 Tiger (he chose that over his Commando😬) my sprag just went wizz😱

Luckily I don’t find the kickstarter ugly or redundant like some so didn’t impair me any. However, once the bike warms up the the dogs lock perfectly and petrol stations (many indeed) don’t represent any fear. Presumably and lube Matt used (I’ve never touch it) goes sticky when cold?

Whatever, I’ll take a gander upon my return
d1164655-00ac-46fa-ad0f-80f9eb85735d.jpeg

Just making sure the transfer gear is stationary when the bike is running. Progress uninterrupted 😉
 
Café au Lait said:
Well bugger me sideways, I now regret making this post, that’ll teach me😂

On day 3 of my 5 day marathon to Pescara, Italy having already lost one companion 2 days earlier on his non starting ‘23 Tiger (he chose that over his Commando😬) my sprag just went wizz😱

Luckily I don’t find the kickstarter ugly or redundant like some so didn’t impair me any. However, once the bike warms up the the dogs lock perfectly and petrol stations (many indeed) don’t represent any fear. Presumably and lube Matt used (I’ve never touch it) goes sticky when cold?

Whatever, I’ll take a gander upon my return View attachment 125131
Just making sure the transfer gear is stationary when the bike is running. Progress uninterrupted 😉
Click to expand...
Is your E/S kit the original one that Matt installed when he built the bike for the original owner? Curious if the sprague in your kit is an "old" style
that has been upgraded.....or if there is a life expectancy on this part......
Jim
 
74 Cafe' said:
Is your E/S kit the original one that Matt installed when he built the bike for the original owner? Curious if the sprague in your kit is an "old" style
that has been upgraded.....or if there is a life expectancy on this part......
Jim
Click to expand...
With the sprag in the CNW kit operating outside the sprag manufacturers specifications, you have to expect a sprag failure sooner of later.
These sprags are of the disengaging type, but in the cnw kit they don't fully disengage, the heel of the dogbone is constantly rubbing on the engine sprocket snout. Throw in that the primary is run dry (no oil present) and you have almost a perfect storm of errors that will make the sprag fail.
 

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