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Collection, Preservation and Display of Old Lawn Mowers

New member, old Atco mower

Hi Everyone,

I recently bought an old lawnmower from gumtree that I know almost nothing about.  It doesn't look like it has the age of most of the mowers that I've looked at on here when trying to figure out a bit about it.  The man I bought it from said it was an Atco but didn't have any more details  I'm hoping to renovate it over the winter and given I don't know anything about mowers, engines or mechanics, I'm hoping I might be able to tap into the vast experience in the club.  

In the meantime, I'd be very grateful if anyone could tell me what make, model and age this is (I'm really hoping it's older than me - born 1981) and whether there is a manual available somewhere?  It seems to say 'four stroke' in a faded decal on the side and is running low on oil (quite a lot seems to drip out of the back once it has warmed up).  Can I just add any Sae30 oil?

Thanks so much,



wristpin Thu, 29/09/2016

Welcome to the club.

What you have is an Atco De Luxe, probably from the 1960/70s and by the looks of your images a 20" cut, but could be 17". If treated with respect it is a perfectly useable machine capable of achieving a good finish on a decent lawn.

SAE 30 detergent oil will be fine. When you get round to working on the engine it will be worth removing the sump and cleaning out  the expected years of sludge. The oil leak from the rear of the engine is probably coming from the valve chest cover partially obscured by the exhaust and carburettor. The cover is held in place by a single stud and nut which may just need a tweak but over tightening can distort the cover; but a worn engine can be expected to expel some oil mist from the vent in the cover . 

Most of the gaskets that may need for the engine are still available from after market suppliers or from that well known auction site. Some chassis parts are becoming hard to find although some components were carried over to the later Atco Commodore. The 14" and 17" were OK machines but in stretching the design to 20" some weaknesses started to become apparent. In particular the traction or landroll clutch (under the side cover) was prone to wear particularly if the chains were ove tightened.…

TimF Thu, 29/09/2016

Hi Wristpin,

Thank you very much indeed for your quick and amazingly informative reply.  I really appreciate you taking the time to help me out so thoroughly.

Good eye for measurements too - the cylinder is 20 inches in width.  The left-hand clutch lever does have quite a lot of travel on it and needs a little prod to get back to being fully open, the petrol tank is far from well-sealed either on top or on the bottom, and I accidentally ran over a screw the other day that brought the machine to a halt and dented the cylinder.  I'm hoping none of these are things that need attention before the winter (I've already replaced the fuel tap and hose and the cork washer on top to try to stem the flow - think plumbers' tape is next to try)!

Many thanks again,



wristpin Thu, 29/09/2016

The left hand, traction clutch, lever is assisted in returning by a wishbone Spring on the cable under the   Main clutch cover.   Contributive cause of a lazy return can be a sticky push rod in the traction clutch . To check that it is necessary to partially dismantle the traction clutch . A word of warning, the outer cover of that clutch is easily removed by undoing three screws but at that point stop and observe the 52 ball bearings between the friction plate / sprocket and the centre hub. Disturb it and there will be balls everywhere, so try not to!

The push rod is in two sections with a ball between them. Remove the outer that you can grab with fingers or pliers and squirt some thin oil into the orifice - this should ensure that the rods are free moving.

TimF Fri, 30/09/2016

52...  Just in case I think I might leave attempting that for a few more weeks!  Got the oil yesterday and will drain down and re-fill this weekend.  The instruction manual is brilliant - I don't remember getting instructions for anything previously that included reference numbers for every single bit of the item down to the last screw!  I might do the air filter too and some general lubrication.  Thanks again Wristpin.