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Collection, Preservation and Display of Old Lawn Mowers

Suffolk Colt chain

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Hi all, recently acquired a Suffolk Colt which I believe is 1970's. Non-runner and requiring some work. 

Managed to sort out most of the issues, clutch shoes rivets had popped which is likely the reason that the starter assembly was damaged etc. 

Final thing, I've ran out of adjustment on the drive chain and would like to sort it out. Can't get a full link out unfortunately,  I know half links are an option but was thinking of a new one. Does anyone know the size / pitch of chain I need to buy? Done something similar on a Hayter 2 and just bought a length of chain which was considerably cheaper.

Many thanks :)

 

Forums

wristpin Tue, 20/04/2021

Chances are that either the cutting cylinder had been reground enough times to reduce its diameter or that the bottom blade / bed knife is worn out. The problem with increasing the chain length is that you may then find that the cutting cylinder spindle hit the bottom of the slot in the chassis side plate - so you then have to start filing that out - or you run out of adjustment on the bearing carriers and have to go on the hunt for longer screws.  

Seen it all, over the years! Possibly the better cost / time sensitive solution would be a new bottom blade but without a cylinder grind, that’s like renewing one blade of a pair of scissors ( apologies to Hortimech).

To go back to your original question, the chain can either be standard  1/2” x 3/16 bike chain with doggy bone shaped links or, on later machines what I describe as flat plate 3/8” chain. Best course of action is to take your chain to your local bearing / transmission parts factor and make use of their hands on expertise.

hortimech Tue, 20/04/2021

There are two different sizes of chains used on Suffolk Super colts, so a picture of the chain will help. However, running out of chain adjustment usually means the cutting cylinder is wound down against the bottom blade. This is usually because either the bottom blade and/or the cutting cylinder is worn out, again a few clear pictures will help.

 

Trebus Wed, 21/04/2021

Thank you for the responses. It actually cuts well enough and cutting cylinder to bottom blade mating seems acceptable.

The chain is too long where so at full adjuster tension it is too slack. It works ok like this but mechanically noisy and I'd rather sort. Sadly not sufficiently slack to remove a link and still join it. So my thoughts were it has likely stretched and a new one would cure it. In normal times I would have done exactly as recommended, take the old one in to be matched up.

Apart from this she's operational, ticks over like a Swiss watch.

wristpin Wed, 21/04/2021

Ah, too long; could be stretch or could also be wear  in the spherical bronze bush supporting the clutch shaft and top sprocket. Try lifting the top sprocket to check for wear. An image would be useful to show the positioning of the tensioner.

Trebus Wed, 21/04/2021

Thanks Wristpin. I'll check the bush, I think it's OK as I've had it out and didn't notice much play other than end float as expected.

So I believe I have the 3/8 x 1/2" chain, reason being I've come across what is obviously the later type of chain and sprockets in a spares box. So one option could be to transplant these items on and give it a go. 

Picture of how it looks currently. 

wristpin Wed, 21/04/2021

The tensioner would normally be the other way round so that the slotted bit lies between the two raised guides in the side plate casting but I don’t think that will make much difference to your problem as it looks as the chain is almost against the chain case securing stud. 

The chain that is on the machine looks like 1/2” x 3/16. It should be available from your local supplier .  The difficulty of buying a crank/stepped link on line is the pin size. With the majority of cheap chain now being made in Poland and India etc there appears to be no standardisation on the pin size . I used to buy common chain sizes in 15m rolls and made sure that I ordered a good selection of connecting and cranked links with each roll as the next roll that I bought was likely to come with different diameter pins.

 

 

 

DJD Wed, 21/04/2021

I often used to find maybe owner had fitted chain wrong side of plastic tensioner, some seemed to think it was actually a variation on adjustment. Lack of proper lubrication will tell, it's not often that a chain will be this loose and bottom blade not worn right out also, unless of course sand or soil has entered chaincase and made things even worse by acting aqs a kind of grinding paste to the chain and sprockets

Odd as it may seem to us converts, some odd folk actually hate using mowers! Then treat them accordingly, it would seem.

Trebus Thu, 22/04/2021

Thanks for everyone's suggestions. After discovering the spares I've successfully changed the complete chain and sprockets for the later type. While still not perfect, I now have an acceptable solution with the adjuster and the clattering has quietened down.

I may invest in a new chain at some point but for now it's good enough.