Atco 28/34

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mikehpw1
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Atco 28/34

Hello

Does anybody have a diagram or pic  showing the full throttle cable route and linkage set up on this mower. Its a MK25 engine. Also what thread are the screws on a standard V carb BSF or UNF thanks

wristpin
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Not sure whether this is what

Not sure whether this is what you need but  the governed throttle is installed in the inlet manifold and is independent of the carburettor.  its a fairly simple set up and the individual parts and links etc can be picked out from the main illustrated parts list page. Strangely the governor spring is illustrated but seems to be ignored in the listing.

https://www.dropbox.com/s/8hv53h1odaf2atx/Atco%20Groundsman%20Villiers%2...

EDIT a bit more

https://www.dropbox.com/s/nano52n09k51t4s/Villiers%20Mk25%20C25%20carbur...

mikehpw1
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Morning Angus

Morning Angus

Thanks for prompt reply. Unfortunately I have a V type carb and none my drawings show any details about lever, cable route or how the cable attaches to the engine around the area of the carb. I assume I’m missing some linkage parts to go from governer arm to cable 

regards

mike

wristpin
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Long time since I’ve seen one

Long time since I’ve seen one in the metal but my memory is that the throttle cable goes straight into the carburettor and is connected to the slide and that the engines internal Governor is connected to the manifold butterfly by a rigid link.

mikehpw1
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Second attempt. This is my

Second attempt. This is my set up

 

wristpin
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We need to know the back

We need to know the back story - has the machine ever run with you ? Was it all apart when you acquired it etc etc 

I think that your linkage has been “ got at” or incorrectly assembled. If you look at the position of that little right angle bracket that anchors the spring , it’s positioned in such a way that the spring is not able to exert much pull on the arm to oppose the shutting action of the internal governor.

Can we see the rest of the carburettor and the throttle cable? 

I suspect that the kinked arm should be nearer horizontal and that the spring should be directly hooked into what appears to be a tiny hole in the short end of the arm and that there is a missing long link to connect the long end to the manifold butterfly. 

hortimech
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Cannot be 100% sure, but I

Cannot be 100% sure, but I think that is the wrong engine, it has been such a long time since I saw one. However, I seem to remember that every 28/34 inch Atco fitted with a Villiers MK25 had a slide carb with the governor in the inlet elbow. That engine appears to be for a stationary application, or to put it another way, it never had a cable. Also the muffler is wrong.

[edit] okay after thinking about it, I am now 100% sure that isn't the correct engine. Delving into my memory I seem to remember that if you wanted to have an adjustable throttle on the MK20/25, you needed a cable that, at the the engine end, replaced the adjuster (the one attached to the spring) shown in your left hand picture.

wristpin
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okay after thinking about it,

okay after thinking about it, I am now 100% sure that isn't the correct engine. Delving into my memory I seem to remember that if you wanted to have an adjustable throttle on the MK20/25, you needed a cable that, at the the engine end, replaced the adjuster (the one attached to the spring) shown in your left hand picture.

100% ! its a constant speed engine for an industrial application and in addition the governor/ carb linkage has been messed with . I was waiting for the OP to to come clean!

Here is the variable speed kit that Villiers would have added to Atco's order. It replaces the fixed governor spring anchor with a cable control.

mikehpw1
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Morning Angus

Morning Angus

im learning that in the mower world anything’s possible, however I can’t see how the engine could have been changed, there’s no evidence of different mounting holes or additional brackets etc. It’s a centre kick start with flat steel side frame. The brackets for the kick start mechanism could only fit the mk25 and the throttle kit you posted is for a tube frame, a later model. There is a bracket on the frame for a lever and I have a lever that fits it. It all looks to perfect to have had an engine swap. I’ve just noticed that the manual I have from OLC is not complete, the pages of the engine are missing so I’m looking at one from the mower  museum, they have a copy and if it’s the right one I’ll buy it. I’ll let you know cheers 

hortimech
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Perhaps when I said that was

Perhaps when I said that was the wrong engine, I should have said , that is the wrong version of the engine.It might be that it is a very old Atco 28 and they originally came with a V type carb, but I have never seen one. Every 28 and 34 inch Atco I have seen had a muffler that turned 90% to the right and a slide carb that turned to the left. For an idea of what it should look like, see this parts list here: https://www.oldlawnmowerclub.co.uk/sites/default/files/opmanual/Atco%20H...

mikehpw1
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Hi

Hi

yes, I think you’re right my 28 is older all the pics I’ve seen are with the slide carb. I’m thinking it is a one speed engine but the bracket for the throttle lever would suggest not. Someone will turn something up soon I hope, I’ve prity much completed resto and about to start rebuilding, would be good to sort this out first though cheers anyway 

hortimech
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Whilst, your engine might be

Whilst, your engine might be the one fitted from new, I am not convinced. From my understanding, the 28 inch Atco was first produced in 1960 and I started work as an apprentice lawnmower mechanic in 1973 and I never saw one that wasn't fitted with the S19 carb (remembered its version now) and the bent muffler. I also cannot see how you could control the speed of the machine without a throttle and you really need to control the speed of this machine, especially if a trailing seat was fitted.

I would surmise that the original was damaged in some way and a replacement engine was sourced, but it wasn't quite the correct engine. 

wristpin
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As with many engine

As with many engine manufactures, they built a base engine and the OEM would order it to their own spec eg exhaust, speed control and type of starter etc. In service, replacement engines would sometimes be available in that spec but in other times as a base with a "remove and add list". Your engine is a basic industrial engine as would have been supplied for fixed speed applications such as concrete mixers, pumps and elevators. A degree of speed control from idle to run could be achieved by fitting the kit that I posted earlier which replaced the fixed governor spring anchor with a cable tensioned one; adequate for industrial applications but not suited mobile ones such as lawnmowers.   Its difficult to see from your images but I'm fairly sure that the fixed speed set up has been messed about with , possibly in an attempt to make it "mower friendly"

Hortimech's memories are right on the mark - born out by the following images.

 

mikehpw1
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Hi

Hi

yep, I’m thinking the same. I had a chat with a very helpful guy in the museum at Southport. They have a manual for sale for the 28/34 ( OLM manual isn’t complete) He kindly looked through it for me and confirmed that the carb was a S19/2 and controls just like your image. So now I’m on hunt for the right carb and exhaust. My first search turned up nothing, could the S19 go by another name? 

mikehpw1
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Thanks for that. I think the

Thanks for that. I think the S19/2 carb is an Atco number any idea what that translates into Villiers models ?

wristpin
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You could well be right as I

You could well be right as I can’t find any reference to S19 in any Villiers publication. May well be worth a call to Paul Child at Meetens.

hortimech
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For once, I have information

For once, I have information you don't have ;-)

The S19/2 is a variant of a motorcycle engine carb and if you can lay your hands on a small book called 'The book of the Villiers enginge' by C.Grange, it is shown in there on page 48. The '/2' just means it has a choke.

 

wristpin
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Always willing to learn but

Always willing to learn but the recall ain’t what it was.

Re the motorcycle connection, it may be worth looking at the Villiers Parts website as George has several different motorcycle related Villiers carbs illustrated. I did have a look yesterday but having failed to find any reference to S19 , gave up. 

mikehpw1
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Morning 

Morning 

thank you all for all your help on this, I now know what I need. One last thing, the 28/34 manual on here is incomplete does anybody have a complete copy? Thanks 

mikehpw1
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Hi

Hi

i have that book, it does show the diagram but it’s not helpful with the set up and tuning as mine as you said has a choke. I’ve now had the engine running but it  hunts at higher revs. If anybody body has an info on set up or adjustments I’d appreciate it. Thanks