CNW e start conversion, sprag failures

trident sam · 2026-07-27T06:25:30-0600

Hi Peter, not been finished yet, let you know when it's up and running. Bad luck with your bike- I do know the feeling, primary chain let go on my T160 and chain wrapped up and bent the crank. Luckily SEM were able to straighten it., also smashed all the primary gears and inner/outer case

milfordite · 2026-07-27T06:38:55-0600

So my sprag died as well, just installed a sprag from Ali Express. We'll see how it goes. I lubed it with sprag grease as well.

dobba99 · 2026-07-27T06:41:38-0600

milfordite said:
So my sprag died as well, just installed a sprag from Ali Express. We'll see how it goes. I lubed it with sprag grease as well.

Mk3 or an earlier commando with a CNW kit?

dobba99 · 2026-07-27T06:43:14-0600

trident sam said:
Hi Peter, not been finished yet, let you know when it's up and running. Bad luck with your bike- I do know the feeling, primary chain let go on my T160 and chain wrapped up and bent the crank. Luckily SEM were able to straighten it., also smashed all the primary gears and inner/outer case

What make of chain was it that broke?

worntorn · 2026-07-27T07:18:50-0600

dobba99 said:
Afternoon Sam
I take it you installed the RC sprag in your Mk3? If so, how many starts have you got on her now?
I got to over 150 odd starts and then a conrod let got on the M1. Smashed the crankcases to bits, snapped the cam, broke a tappet , smashed the plates either side of the isolastic housing and put a dint in the exhaust pipe! I,ve spent the last 6 weeks getting Mitzi back together.

Was this a stock conrod that broke?

HouTexNorton · 2026-07-27T07:33:36-0600

dobba99 said:
That could have been a failing battery or loose battery lead/s. was it the solenoid clicking?
Until Matt at CNW or somebody else comes up with a redesign of the sprocket/sprag/drive gear you are stuck with the heel dragging problem with these kits.

No battery issue, it was definitely the sprag. The bike started right up as soon as I changed it out with the replacement sent to me by Matt. I was just concerned that it failed so quickly.

trident sam · 2026-07-27T08:29:00-0600

dobba99 said:
What make of chain was it that broke?

Renold, I use Merc chain from chain man now

dobba99 · 2026-07-27T10:29:34-0600

trident sam said:
Renold, I use Merc chain from chain man now

Same here, been using the iwis duplex chain for the last ten years.
Stock rod that broke @ 93k miles
Anybody who asks I now recommend changing original rods at 80k

robs ss · 2026-07-27T15:03:41-0600

trident sam said:
I expect the sprag Im got from from Peter (Dobba 99) will last a long time, I still kick the Mk 3 into life from cold and will continue to do so. I always make sure the battery is in really good shape.

Yes, but if my understanding is correct, the "dragging heel" syndrome means that the wear is largely irrespective of the number of starts. The wear will be related to running time.
Of course, each time you use the e-start you "cycle" the springs.
Cheers

CNW e start conversion, sprag failures

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