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Collection, Preservation and Display of Old Lawn Mowers

Atco b30 , clutch issue

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Asked by the local bowling club, if I could help out with their back up mower ( non runner)

its now running beautiful, but problem appears to a clutch problem, blades not engaging 

when appropriate levels pulled. The plates in the housing appear to have castle tops and have

a fair amount of play when not engaged. When pressure is applied to the plates they are tight and the 

blades make an effort to turn but don,t. I'm assuming the plates need replacing ( unless I'm missing something).

Would it be easier to remove the engine and separate clutch or take off the chains and chain gears?'or is there another way,

to replace the plates. Some photos below of machine.

Forums

hortimech Sun, 26/05/2019

If the plates are compressing , but drive isn't being transmitted or is slipping, then it sounds like the pin inside the clutch has sheared, which was a common occurrence.

You will need to remove the engine and then remove the clutch housing, if I remember correctly, the screw in the end of the clutch shaft is left hand thread.

Just be methodical and take notes and you shouldn't have any problems, except for finding a replacement spiral pin ;-)

 

 

wristpin Sun, 26/05/2019

As per Hortimech's comments the most likely cause of your problem is that the pin (20) securing the square adaptor (21) to the clutch shaft has sheared . Originally these were a roll pin but by the time your machine came along they had been upgraded to a slightly larger diameter Spirol Pin (trade name) which as its name suggest has a stronger "swiss roll" spiral conformation rather than being a hollow roll pin.

H comments on the possibility of a left hand threaded screw - by the time your machine was made that aspect of the design had been changed.

Once you've got every thing anchored and assembled, just make sure that with the clutch engaged the two thrust bearings (6) are clear of the withdrawal plate (16) by at least a mm  

From memory the Spirol pin will probably be 6mm - measure the old one, and had a part number pf F016L16272.  The same design has been carried through to Allett's version of your machine and the pin probably carries the same part number. They market their version as the Buckingham.

https://www.dropbox.com/s/7iazni1v28ogdeq/Atco%20B30%20and%20Royale%20M…; ,

Flowerpots Sun, 26/05/2019

Thanks gents, for your help and advice, will take apart and give you a update.

wristpin Sun, 26/05/2019

Just a parting observation. Is your head on image of the machine actually of a 30"? The reason I ask is that not only does it not look right but there don't appear to be enough "divisions" in the cutting cylinder and I've never seen a 30" with that ratchet on the rear roller sprocket which would be more at home on a B20 Club or Golf Green Special to drive the transport wheels?

Flowerpots Wed, 29/05/2019

Yes your right, I was told it was a b30, Because I didn't have the front, could identify it, it is indeed a club B20 I/c professional. 

Fixed up and running, spirol pin was damaged and 2 of the coupling plates had big cracks in them, so replaced the 3 washers and plates.

just one last question, it has a Briggs and Stratton interkpro OHV 6.5 HP engine, although it runs great,

been a perfectionist the idle appears a little high, not put a tach Meter on it yet but it would say it's greater then 1750rpm, it has a mechanical governor, what would be the normal idle for his type of machine be.

thanks again.

 

 

 

 

wristpin Wed, 29/05/2019

As far as I know that horizontal crank engine did not have a governed idle so the idle speed will be determined by a combination of the throttle stop screw and the idle mixture screw ( if adjustable). The mechanical Governor only looks after the top speed and is probably set to about 2800. 1750 is the specified idle speed but does “ sound quite fast” . You can probably lower it a bit but you may find  the engine bogs down or stalls when the clutch is engaged . Those Atco clutches were always quite sharp and in latter days weren’t helped by the various Operator Presence Control (OPCs) bars fitted to comply with various safety standards.