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Collection, Preservation and Display of Old Lawn Mowers

Atco Barrel Mower Info


hi all,

im new here and in Australia and have acquired this Atco mower.

im after some info on it. It has a Villiers engine on it, but I don’t know what model. I’m looking for any info you guys might have as I’m hoping to rebuild it. It has no compression. I’ve done up 2 up Villiers mk10 engines, but this one is different. 

Ive attached some photos. I’m thinking it’s a Mk7, but not sure. If it is, can you get parts for them? The mower photo is a file photo as I took the engine off before I got a chance to take one.

Any help appreciated 


gtc Wed, 28/11/2018

Welcome to the site. The ID plate indicates a 17 inch cut, manufactured in 1959/1960. Member 'Sir_chook' is fairly well versed in Actos. I'll flag this post to him and hopefully he'll reply.

sir_chook Wed, 28/11/2018

Hi Andrew and GTC,

This mower indeed has the Mk7 4 stroke 1.3hp. Generally, parts can be obtained from sources in England. Depending on what you need you may be able to source the parts in Australia. Before looking to source new parts check the valves to make sure that they are seating properly.

Kind regards,

Sir Chook

AndrewBissett Wed, 28/11/2018

Thank you wristpin. Great info. Do you have any settings for timing on them? I have them for the mk7, I’ll make sure it’s the same for the d7

AndrewBissett Thu, 29/11/2018

No that’s great thank you! The only thing I didn’t check, when I did the mk10, there where 2 punch holes on the cam and crank sprockets to match up when the crank went back in. I didn’t look when I pulled the one out of this mk7, but I assume there are holes to match up again?


thanks again

wristpin Thu, 29/11/2018

The book shows a “centre pop” mark on one tooth of the crank gear and another next to the valley between two teeth on the cam gear. If the illustration is accurate the mark on the cam is adjacent to a hole in the web of the gear.

AndrewBissett Fri, 30/11/2018

Thanks Wristpin. Sounds the same as the bigger ones, just match up the punch marks. Thanks again

AndrewBissett Mon, 03/12/2018

Hi, just another query, does the book for the mk7 specify tensions for the nuts where the con rod joins the crank shaft?


sorry to keep hassling you!

AndrewBissett Mon, 17/12/2018

Ok so after some more advice. I’ve got parts and started rebuilding it. I pressed out the old crank shaft bearing bushes and pressed the new ones in, installed the crank but it’s very tight. Is this normal for those bush type bearings. By bush type I mean a bush, not actual ball bearings. They seem tight, but I guess they have to be for a start?

wristpin Mon, 17/12/2018

With the crankcase split did you happen to try each half on the crank before bolting them together? If they were free until joined it is possibly an alignment issue . Are the halves dowled as well as bolted ? May be worth slackening the bolts between the halves and the nuts holding the cylinder barrel if fitted and give every thing a light tap with a soft hammer while turning the crank.

I have no specific knowledge of Atco’s assembly procedure but from memory the crankcase halves are marked with matching numbers so it is possible that original assembly involved slightly under sized bushes which were then line bored ( or reamed) while the halves were initially  bolted together before the crank was installed.

EDIT. Just realised, looking at your earlier images , that you have a 4-stroke. For some unknown reason I had it in my head that you had a two stroke. That makes a nonsense of much of the above post! 

So back to the matter in hand, have you still got a bit of crankshaft end float? If not, the crank could be under longitudinal compression , hence the stiffness. To achieve a bit of end float you will need a thicker crankcase cover gasket. Some engine manufacturers supply two or three different thicknesses of gasket or a pack of the same thickness to use in multiples. To the best of my knowledge Villiers did not do this so you may need to calculate what is needed  and make the appropriate gasket.

End float - I've just grabbed a couple of Villiers manuals and they are both totally silent on the matter; so unless you can find a figure or anyone else can contribute, I'd suggest  2 - 8thou cold.

FURTHER EDIT !! Having done a bit of "wet day" research and gone back through your earlier posts to re- discover that you have a Villiers Mk7 , I've found an illustrated parts list which shows that the end float is set by varying the thickness / quantity of gaskets between the magneto back plate and the crankcase. Part 68 available in three thicknesses. However I have yet to find a figure for the recommended amount of end float.…