Atco 14 Light - Clutch Removal from Crank Shaft.

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thenewts
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Atco 14 Light - Clutch Removal from Crank Shaft.

Hi all, wondered if anyone could point me in the right direction on this one.

I have what I'm sure is an Atco 14 light. Unfortunately it doesn't have manufacturing plate on it, so a positive ID and an age range would be appreciated from those more knowledgable on the subject...

My main issue is she's pretty much stripped down but I just can't get the clutch dog / housing off the crank shaft. I've tried unscrewing it assuming both left & right threads, and I've had a bearing puller on it under the assumption it's press fitted on. I'm just wary of giving it any substantial force until I know I'm turning / pulling it in the right direction...

Any advice appreciated, thanks.

 

wristpin
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Joined: 23/05/2012 - 22:09
The engine rotates clockwise

The engine rotates clockwise and it tightens onto the clutch basket as it goes, so it will undo anti clockwise. However you must be extremely careful how and where you grip the crank as it is of 3-piece construction with the webs pressed onto the big end pin and if you apply too much force in the wrong manner you can twist the webs in relation to one  another and its a b of a job with V blocks, dial gauges and a certain amount of luck (sorry skill) to re-align them. Don't ask how I know sad

EDIT.  Been thinking about your problem since posting my answer yesterday evening  and had a hunt around this morning and found a similar Villiers crank.

The one that I found has a dog, not a basket and is clockwise screwed onto a taper. with the dog almost off you can see the amount of taper that is hidden inside it when tight. To undo this dog I had to give it a few sharp hits on the anvil and then punch against the protrusions to both turn it and free it from the taper.

Looking at the amount of thread protruding inside your clutch basket, I'm guessing that there was a nut .That suggests that the basket may be on a taper. The basket does not lend itself to shock treatment to free the taper so perhaps support the boss on something solid and give the opposite flat some sharp blows with  a heavy hammer and drift . That may release the taper if that's all that's holding it but it may also be screwed  in a similar way to mine, and the nut - if fitted - just being belt and braces.

Dog fully screwed onto the crankDog fully screwed to crank , no taper exposed

 

Dog just hanging on to last thread showing taper Dog unscrewed to last thread showing the amount of taper exposed.

Threaded section and taper.

  

 

thenewts
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Hi wristpin, thanks for

Hi wristpin, thanks for taking the time to help on this one.

As it happens I finally sorted it late last night. I was watching a Youtube video of a guy who's got the same engine just mounted on a stand. He didn't have anything on the end of the crank shaft, where my clutch basket is, and I could clearly see it was tapered. This was the vid: https://www.youtube.com/watch?v=7l-bXz9FBf0

So, armed with the knowledge it was pressed on I tried the gear puller again. I had to improvise a jubilee clip style band to hold the puller arms in place against the curved bottom of the clutch basket and placed a heavy duty washer on the end of the crank shaft thread to prevent damage. I wound it up to a decent amount of force and left it for a minute.  Nothing happened. Then I grabbed a Mapp gas and started heating the bottom of the clutch basket - it popped off after 10 seconds of heat. What a great sound that was!

Hopefully this may help someone else out in the future.

Completed the strip down today, painting starts tomorrow :0)

wristpin
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Good result - it’s a great

Good result - it’s a great sound when a taper releases! Fortunate that the basket is strong enough to take the pull without distortion. With the knowledge that the basket is not screwed on , the release could probably be achieved without the “ pull”  by shocking the boss. A possible better option if a good source of heat is not available.