Whizzer NE5 auto-clutch arm mods...??



Howdy, folks,

Today the UPS truck arrived with some replacement collets and end mills for my little Taig vertical mill. So I quickly pulled the Whizzer out of the garage and went back to work on the clutch. The pulleys were out of alignment by around 1/16 of an inch... Not a good thing..

It was a bunch of fun getting the mill up and running again. (Why it took a bunch of time for me to get around to doing that is a long story.) But, included here are a couple of pix.

First I milled off a bit of the inward side of the pivot-end of clutch arm to get it flat. And then I went after the outside of the clutch-end of the arm. With luck, it'll work. If not, I'll shim it, or mill off some more.

So, now, the questions... (I have a spare clutch arm, so I can always go back to square 1.) Does anyone disagree with my approach to the problem?

There's a free-moving bushing in the pivot end of the system. How freely should that be able to turn? Should I put a bit of Loctite on the pivot bolt threads?




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Hi, Bill..

Are you saying that the bushings in the crank-case, on the pivot end of the clutch arm, should _not_ be free to turn in the engine flange??

One of them on my bike comes out easily.

But something that concerns me as much is, when I tighten down the pivot bolt a bit beyond finger-tight, it gets so locked-up that the pivot end of the arm doesn't want to pivot any more!

Any ideas there?

Anyhoo, the first trial fit of the clutch showed me that I still had to cut off some more metal from the boss on the arm to get the pulleys in line. So I did that tonight. Tomorrow I find out where I'm at now...

NE5's run ok. But gettin' 'em to whatever idea of perfection you might have, takes work.

Fortunately, it's work I enjoy...

I think I'm nearly done...

Today I found that I had to mill off a bunch more metal from the clutch end of the arm. And, for good measure, I milled some off the pivot end of the arm as well; in hopes that I could get the lock nut tight and still have it swing fairly freely.

It looks like I, finally, have the pulleys aligned. But it took milling off quite a bit of metal to get it done. Cutting off that much metal would have scared me. But I had a spare clutch arm, so I threw caution to the wind.

Attached are a couple of pix of the "hopefully" finished part. Take a look at the first pic to see how much metal I had to shave off compared to a stock clutch arm.



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Hi Del all of mine have to be tapped out ,I havent gotten any that fall out..Bill

Hmmm..., Bill,

I'll have to keep an eye on that. Worst case, I'll chuck the loose busing up in the lathe and knurl the outside a bit to get a tighter fit in the case.

Or should I clean it up and apply a bit of loctite?

Hi del thats looks like how far I have to cut mine ..Looks Great Bill

That's good to hear, Bill,

It was gettin' scary for a while there when started to see how much metal I was having to remove. But, it looks like the newly modified arm is working fine.

And, strangely, the engine seems to idle a bit better... I could be hallucinating, of course. But maybe it's because getting things lined-up reduced drive train friction enough to let the engine idle easier. A puzzlement...

A few years ago a dear friend of mine, who's a retired machinist, suggested I buy a little Taig lathe. The little machine taught me a lot. I still use it for turning small parts.

I continue to accuse my friend of "ruining my life..." He laughs, and knows what I mean... Being able to cut metal with some precision, opens up possibilities for making, and re-working, parts that I would have thought impossible before.

The Whizzer clutch arm was re-worked on my Taig bench-top vertical mill. I continue to be amazed by what that little mill is capable of doing. Though I'm not sure that my skills are quite up to milling off the cylinder head on the Whizzer....

Howdy, Bill,

If you do the bronze bushing for the pivot arm mod, let us know how it goes. That sounds interesting.

Meanwhile I'll do the occasional inspection of the the pivot arm to see if the loose fitting bushing is becoming a problem.