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Collection, Preservation and Display of Old Lawn Mowers

Ransomes Auto Certes

Hello to all,

I have acquired a Ransomes Auto Certes mower from my neighbour who was going to throw it away?

It seems that it has little or no compression so may be the ring will need to be replaced, to do this it looks as though the clutch mounting will have to be removed to access the side cover does anyone have any idea how this is removed from the shaft?

The machine has been stood for over 20  years in a shed, the engine is a BSA F12 with an Amal carb,

Any ideas anyone

Thanks in Anticipation

Aled Wed, 17/08/2011


Ransomes Auto Certes is a very good mower, as is the engine on it, so I certainly don't reccomend you throw it away!

Anyway to get the clutch off simply undo any bolts securing it onto the shaft (I don't think there will be any) and then use a flywheel puller to remove the clutch.

Consider however the clutch acts as a second flywheel, on these engines I don't think you can feel the compression as well as on any other engine because the inertia the clutch creates gives the engine a smoother turnover. You can check using a compression tester such as this to see if the engine is producing sufficient compression. Those things are worth the money especially if you're working on cars or motorcycles as well!

If you've not stripped the engine down as far as the cylinder head you might also want to consider the fact that the exhaust valve may be stuck, since it's been left so long the exhaust valve in particular on small engines tends to seize open so there will never be any compression in the combustion chamber. The way to rectify that is to make sure the valve is at a point where it should be closed, oil the valve stem and then lightly tap the valve shut with a hammer, repeat until it opens and closes freely.

Hope I helped!


hillsider Thu, 18/08/2011


I agree with all that Aled has said re the mower that you have collected, I think you would be wise to investigate the condition of the valves by removing the cylinder head before taking the engine off the mower as these can often be the cause of loss of compression on small engines.

Spare parts and gaskets etc are available from Meetens Engines Ltd if you need them I have always found them very helpful



Botech Thu, 18/08/2011


Thanks for the reply, this is what i thought might be the case but wanted some one to confirm, also as you mention the exhaust valve was stuck in the open position, This I freed off and is now working as it should, however the compression was still the same hence my attention being directed to the rings, hopefully I will get around to this at the weekend, will let you know how I get on

Thanks again.

Botech Thu, 18/08/2011

Hi Ray,

Thanks for the reply, as the engine has been on and off more times recently the I care to mention recently as it is easier to work on on the bench,( would need arms like Garth if I wanted to lift the whole thing lol!!)

Anyway as I have mentioned the lump is off and as it is I will check the rings out nothing to lose by checking them at this point.

Strange how things transpire, since I aquired this machine a few months ago and doing a little investigation work I have found out quite a lot about this type of machine,

I have also recently purchased another Ransomes Mower from Ebay as a none runner I think this could be a Marquis but it has no plate on it like the other one.

This one I got for £10.99 and full of petrol the guy could not get it going !!! RESULT, got it home

looked at the plug it had in, wrong one, changed it, started second pull. I now use this to cut my lawn, it cuts a dream if I could get the pictures to upload I will put then on but not having much luck with that at the moment,

You can also get some part from villiers for these engines

Thanks again for the reply will keep you posted