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Atco Groundsman

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Maverick.uk Tue, 19/07/2016

Hi Everyone,

Im hoping that you guys can help me to successfully get an old mower to a working condition to be put back into use at our football club.

I have been at the club for about 4 years and have found at the back of an old shed an Atco Groundsman (i think from research ive done), This has a electric start via belt driven starter. It was non functioning and the carb laid on top of the engine with throttle barrel seized in the body.

I have since removed carb and dismantled and cleaned, I managed to free off the seized barrel so this now moves up and down with throttle movement nicley. I checked engine over and had a spark so all seemed in order. I had to replace fuel lines and fuel taps and with all this done and a fresh battery installed it turned over and kicked into life (sort off).

Now i can only manage to open the throttle by about i guess 1/4 and there after it dies, if i drop the throttle again it will continue to run. Doing some research already it suggests that it maybe related to the height of the fuel in the chamber. I recall the needle valve and brass falcrum piece inside the carb was a very crude affair. Searching around i can find no information on the correct setting for this.

So i would be grateful for any input on this issue and also to find out if anyone has a manual of any sort for this machine (none listed on here that i can find) I found a manual for the engine which is similar but not exact (in terms of the carb) on here but its not very detailed with information on setting it up.

 

Thanks

 

Kevin

Forums

wristpin Tue, 19/07/2016

Some images will help but at the moment I'm guessing that your machine has a Villiers ( MK 25?) with a dyna start  which both starts the engine and then charges the battery. 

If you can give a positive identification of the engine we can then try to come up with  settings etc.

Maverick.uk Tue, 19/07/2016

Yes i believe a Villiers Mk25, not got any pictures to hand but will take some next time im at the club.

Thanks

Kevin

wristpin Tue, 19/07/2016

This may be of use

https://www.dropbox.com/s/suhkqdsleytpbfo/Villiers%20Mk250001.pdf?dl=0

https://www.dropbox.com/s/ah5zbr7m8lqllcu/Villiers%20Mk25%20Carburettor…

https://www.dropbox.com/s/371z0aftyv8vt3e/Atco%20Groundsman%20illustrat…

Note that there are some differences between the carburettor illustrated in the Atco and Villiers lists but the information regarding the float lever setting should be a good starting point.

A general word of warning re the metal to metal cone clutch on the Groundsman - be very sparse with any lubrication of the sliding element of the clutch and at all costs avoid oil contamination of the cone and cup faces. Once contaminated they are a pain to clean up as the oil gets absorbed and then continues to "sweat out".

Maverick.uk Thu, 21/07/2016

Thanks very much fro the pdf files,

From the pictures it is definitely an Atco Groundsman 34 with dynastart.

The carb fitted is as in the illustrated parts list S19/2 with hand throttle control.

Hopefully the float setting will be the same as the 'other' carb (picture different to actual carb and non adjustable at the bottom) in the Villiers information. between 3/16" and 5/16"

I will remove the carb and look at the float setting, machine runs very well and will pull along and cut grass but only at low revs, could do with additional revs when going up a slightly incline, but it dies when you open throttle up.

Thanks

Kevin

wristpin Thu, 21/07/2016

That's good. From what I remember , a Groundsman at high revs is more of a run behind rather than a walk behind, but a MK 25 in reasonable condition should have a reasonable reserve of torque at low revs if the governor is correctly set.

Maverick.uk Thu, 21/07/2016

It has the pull behind seat, so i guess with that in tow a faster ground pace would not be a problem :-)

 

Kevin

Maverick.uk Fri, 29/07/2016

Morning everyone,

 

Bit of an update, went to the ground yesterday to have a play. I have uploaded some images of the machine.

I removed again the carb and looked at the float height, according to the information in a previous post i should measure this when pushed up and seated against the valve. On measurement it was at circa 3.7MM and should have been nearer 4.7 to 7.9 depending on what dimension you refer to. I managed to bend the brass fulcrum piece so this measured about 5.5MM and replaced on engine. You are rather limited to how much you can adjust this as the float sits between the main jet screwed into the side of the tube and the fulcrum piece.

I started it and it ran ok in the same throttle area but cut out again when opening throttle more than about 1/3rd. I started to have a look whilst running and what i found was that if i pushed the little plunger (tickler?) on top of the carb it would then rev considerably higher so suggests lack of fuel at this throttle opening? Still not enough fuel in the bowl? Whilst doing this and having my hand close to cylinder I felt warm blowing on my hand, I think from head gasket leak? Lastly I moved to the front of the engine and looked at the governor linkage, again I'm not sure how this works but its clearly linked to the engine and appears to operate a  butterfly system in the intake, this appeared seized so warrants further investigation, although the butterfly is wide open.

Let me know your thoughts.

Also, there is no charging of the battery, meter reads 12.30v with engine running so another issue to look at. Output from dynamo is circa 18V, is there a regulator fitted?

 

 

Thanks

Kevin

wristpin Fri, 29/07/2016

Not sure about your uploaded images - they haven't appeared here.

If the head gasket is blowing , you will have the head off to replace the gasket so why not give the engine a " valve job" while you're in there. That will ensure that another vital factor in the engine's operation is as good as it can be.

Governor. The purpose of the governor is to control the speed of the engine and to enable it to react to changes in load. Basically the governed speed is the product of a " fight" between the centrifugal governor within the crankcase which is trying to close the throttle and the opposing force applied to it  by the throttle cable via a spring - the governor spring.

 

Edit

The images arrived this afternoon!

If you look at the last page of the manual that I posted it shows a conventional car type regulator . May be the contacts are stuck / corroded. Guess that the regulator is tucked away under the cover between the engine and chain case. 

Here's a copy

https://www.dropbox.com/s/371z0aftyv8vt3e/Atco%20Groundsman%20illustrat…

hortimech Sat, 30/07/2016

Sorry Wristpin, that is not a standard car regulator, it is a dynastart regulator, which is a combination of a regulator and starter solenoid and they were a bit prone to failing.

wristpin Sat, 30/07/2016

Fair does. I've never seen one in the metal , just the " lump" in the diagram. Perhaps you will give Maverick the benefit of your experience in testing and setting it up.