CNW Electric Starter Video installation series

swooshdave said:

Be prepared to learn something.

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johnm said:

Ok. So what I did was instal the left side adjuster the same orientation as the right side.

So then I was able to use the long socket method coming in from alongside the wheel on both sides. The right side is easy. The left side requires you to pre mark the flats of the nut so you can count any rotation.

Procedure is loosen rear nut. Push box forward thus freeing up the front nut. Carefully adjust both sides counting flats to make sure the previously set up alignment us maintained. Because there is no weight on the nuts you can rotate them with a long thin screw driver counting the flats. No need for a spanner. Then tighten rear nuts pulling the gearbox evenly backward. This will also lock the front nuts.

I needed to do this adjustment one more time after I had run the bike a few mins because my belt was a touch tight.

If you get the belt right first time then obviously this is all unnecessary but I wasn't that clever.

It's worth repeating Matt says the drive side adjuster isn't required but I like them from my old racing days.

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swooshdave said:

It all depends on how parallel your two shafts are and how much the wiggle.

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johnm said:

No it doesn't.

I made sure the belt was aligned exactly firstly and then always counted flats whenever I adjusted from then on.

So any non parallel should have been accounted for. If the shafts were loose then again tightening from the back on both sides the exact same amount should keep the gearbox in line. It cannot go anywhere else. Plus the shafts are not loose in my case anyway because it was a brand new gearbox case.

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swooshdave said:

The best way to keep a belt running true is to insure both shafts are perfectly parallel. That what I said. That is not open for question. It's physics and we don't question physics.

Now how you achieve that is up to you, and there is room for error.

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johnm said:

I think we are talking at cross purposes.

Obviously the two shafts, crank and gearbox should run in parallel. Plus the two pulleys also machined parallel and aligned.
I don't recall I said they didn't.

I checked and ensured the shafts were parallel and aligned first. That was a given.

I didn't major in physics at uni. But I did do some.

Look at it this way.

Take two shafts which have been checked as perfectly parallel.

Then lock one shaft in place. In this case the crankshaft.

Then adjust the position of the other shaft the gearbox shaft - IN ONE PLANE ONLY - by pulling or pushing BOTH ends of the second shaft in the SAME direction by an IDENTICAL amount say 20 thou.

The two shafts will remain in parallel.

In the case of the adjusters in the video this will not be true because the adjusters do not have identical vectors. Thus adjustment by an identical amount will not keep the shafts perfectly parallel.

But I fitted the adjusters the same on both sides so they move on the same plane and thus identical vectors.

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Fast Eddie said:

John, any starter kit, like yours, that can spin over my 11:1 compression 920cc Commando engine so effortlessly and so reliably has to be worth a few sacrifices here n there !

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G81 Can Cycle said:

Great videos Dave

I thought I might answer one of your questions from the 4th part. Why did we use such a big starter motor? Well there are several reasons. Before we started our design we examined our competitors offering, and we looked closely at the Mark III design from Norton.

At the time of review we saw several problems with the Mark III design and one problem with our competitors offering (the competitor has since fixed the one problem we saw)

One of the problems we saw in the Mark III was overrun of the sprag system. If the sprag stuck or did not release, the engine RPM was multiplied up the gear train, and since the starter motor pinion always stayed engaged, this worked as an overdrive and the motor would turn so fast (possibility of over 20,000 RPM) that the starter would "grenade" from centrifugal force. We have several Mark III examples of this and the destruction of the starter motor and the inner primary. SO we wanted a starter that disengaged the pinion from the starter gear train. There are two ways to disengage a starter pinion, either a solenoid or bendix drive, we chose a solenoid unit. Now all this being said, it may not have been necessary. We have never heard of a competitors starter having a stuck sprag and overunning the starter motor (the competitor's starter pinion stays engaged in the gear/chain drive to the crank) But at the time of design, looking at the destroyed Mark III inner primaries, we decided the disengagement of the pinion was important .

Second reason was backfire protection. In the motor we use the starter motor drives the solenoid actuated pinion via a set of spur gears. One of those spur gears has a sprag on it. So if the engine backfires during cranking the sprag in the spur gear releases and this prevents damage to the starter motor. It does not damage any components, and no disassembly must be done to correct the system after a backfire during cranking. Our main competitor used nylon shear pins to establish this fail safe, and is similar to industrial couplings used on motor to pump application. It works well, but if if it does fail, some disassembly has to be done to replace the nylon pins. So for this reason, I still think this motor was good choice

Another factor in choosing this motor was availability. This motor has been used on Harley Sportsters since the early 1980's. They are very easy to find, and come in chrome and black. The starter is well proven, relatively inexpensive, and has lots of power to crank even the largest overbore or highest of compression engines . We also used this philosophy in the charging system, we designed the kit to use standard rotors and stators allowing end users to choose from a variety of charging systems, and if a failure happens, multiple sources are available to replace the components at a very economic basis.

Overall I am happy with the choice and sales have been good. I do have some second thoughts every time I hear that a potential customer did not buy a CNW starter system because they did not want to delete the ham can air cleaner.

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jsnorton said:

Great videos Dave, thanks for posting them. Lol....i wondered what the little penguin was all about, thought maybe it was his mascot.....lol.

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johnm said:

I think we are talking at cross purposes.

Obviously the two shafts, crank and gearbox should run in parallel. Plus the two pulleys also machined parallel and aligned.
I don't recall I said they didn't.

I checked and ensured the shafts were parallel and aligned first. That was a given.

I didn't major in physics at uni. But I did do some.

Look at it this way.

Take two shafts which have been checked as perfectly parallel.

Then lock one shaft in place. In this case the crankshaft.

Then adjust the position of the other shaft the gearbox shaft - IN ONE PLANE ONLY - by pulling or pushing BOTH ends of the second shaft in the SAME direction by an IDENTICAL amount say 20 thou.

The two shafts will remain in parallel.

In the case of the adjusters in the video this will not be true because the adjusters do not have identical vectors. Thus adjustment by an identical amount will not keep the shafts perfectly parallel.

But I fitted the adjusters the same on both sides so they move on the same plane and thus identical vectors.

Click to expand...

ludwig said:

It is my experience that with perfectly parallel shafts ( static) the belt still has a tendency to run out to the left.
IMO, it is better to point the 2 shafts slightly outwards.
And instead of spending time and money on adjusters and figuring out intricate ways to adjust them, determine the correct position of the gearbox and fix it permanently. Throw the adjusters in the scrap metal bin where they belong.
Less clutter, less weight.
Once set, belts don't need adjusting.

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