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Collection, Preservation and Display of Old Lawn Mowers

Ransomes Auto Certes

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Just bought a Ransomes Auto certes and I am restoring it. It has the Norton Villiers F12 engine and I have a few questions.

Mower was bought as "won't start" but I found that the exhaust valve was stuck open. This freed off easily so no problem there. There is a weak spark when flywheel is turned over by hand, but thei may well be ok on the pull starter when replaced. However i am wondering if I can check the points essily and if so, what needs to be removed and will I need a special puller.?    Carb needs a new float needle and main jet tubular filter, which is essential as jet has a hole not much bigger than the sharp end of a needle. Are silencers available for these mowers or do I make a new one?. I have all the tools to do the job so that does not scare me. Is a service manual for the engine on line anywhere ? 

This is a good mower all round and does not look like it has done much work, so well worth restoring. I worked in the lawn mower shop for five years from 65 to 70 and well remember the chap who built the hand Certes, a Harry Pitcher, who lived north of Ipswich in Tuddenham, where I lived, and I often gave him a lift to work. Good days and a great bunch of guys in that factory.


sparkymike Fri, 31/05/2024

I need to make a new silencer for the sloper engine. I have searched hi and low, but could not find any original types for sale anywhere. The silencer is basically two deep dish pressings with a couple of tubes welded inside for inlet and outlet. The outlet tube has a couple of slots mid postion to let out the exhaust gases. I have made a trial die consisting of a male and female section and had reasonable sucess pressing out one side. However the die material, a hard wood, was not strong enough and the metal left a few grooves in the die. With this in mind I am now thinking of making a proper steel die which should be good for several parts. Is there a call for these.?


sparkymike Sun, 09/06/2024

Some slow progress on the Certes. I have been cleaning down the cylinder and was wondering how I could clean off any surface rust etc. off the centre spindle. I then found a long narrow strip of emery cloth and working this back and forwards while wrapped round the spindle worked a treat and was quick. 


sparkymike Fri, 14/06/2024

Slow progress as I have other more important work to do. The main frame is now painted and I will give it a few more days to dry totally. I was getting the engine ready to fit the cowl and tank and looked at the clutch shoes and I then noticed that I had them the wrong way round according to Ransomes Certes handbook. I had previously greased the shoe pivot pins , so easy job to swap them round. 


chirpy999 Sat, 15/06/2024

Mike re the sloper exhaust  Id be interested in a new exhaust for my Marquis if the price was reasonable.


sparkymike Mon, 17/06/2024

Now trial fit of the landroll clutch and I am concerned that when the three clutch nuts are done up tight to the tubes that are inside the coil springs, the springs are very compressed. To work the clutch by hand it takes me both hands pulling on the clutch lever, in order to disengage it. I am considering adding distance pieces under the tubes to release pressure a tad. However, not sure if this is correct thing to do and more importantly, would the clutch then fould on the side cover.?            Mike.

sparkymike Tue, 18/06/2024

Engine was bolted on, but now off again, as I found out from the parts book that there should be a felt oil seal on engine side of the small chain sprocket bearing.A couple of photos to show progress, even though at times it goes backwards !!


wristpin Wed, 19/06/2024

Your issue with the traction clutch  may be due to incorrect assembly. It’s possible that you have the threaded collar the wrong way round. Ransomes describe it as “securing nut ,clutch”.  The one that has the two holes for the adjusting tool.

sparkymike Wed, 19/06/2024

Hi Wristpin,

will check the collar with the two holes in. I think it is on ok but will check anyway. I am wondering if someone has replaced the springs with longer than standard . Do you know the free length of these springs. I assume same as Marquis? Also do you know the length of the inner sleeves? If either are wrong then that could be the problem. Am I correct in thinking that you tighten the three clutch nuts up so they are tight on the inner sleeves ?


wristpin Wed, 19/06/2024

I’ve come across them with the collar on the wrong way round so it wouldn’t surprise me to hear that it is your issue.  Anyway, I’ll get those measurements for you tomorrow. While we are on that clutch , make sure that it’s got the ball bearing between the two push rods. Always worth making sure that the adjusting bolt and lock nut are freed off and lubricated before you get too far on assembly and too much paint on them.

sparkymike Thu, 20/06/2024

Hi Wristpin,    Measured the tube and spring. Tube is 1.063  Spring is 1.375. Boss of the collar is facing outwards. Ball in place between the outer rod (engine side) and inner rod with flattened end. Other thing could be brand new clutch pads, maybe too thick. When worn, clutch springs would be slacker. I will measure them and post. One other point re. clutch, when holding the edge of the large toothed pad carrier, I can move it side to side around 1/32" to 1/16" . Do I need to replace the inner bush, or ring bearing. (or maybe both.) Restoration slow going at the moment due to building work I am doing.

wristpin Thu, 20/06/2024

Dug out an old clutch , Springs and tubes are within a hair’s breadth of yours .

Was the clutch working ok before you stripped it out?
I’m still thinking an assembly issue.




sparkymike Thu, 20/06/2024

Mower was not running when I bought it, so no way of telling how clutch worked. I now have all the clutch parts seperated and only problem so far is the brass bush that runs on the steel bush is not up to scratch and I will have to find or turn up a new one. The steel bush is measures a thou under 0.8125, so that seems ok, being hardened. I will measure the clutch segment pad thicknesses now. I also made sure that the ball bearing is between the two rods. The clutch segment pads are 0.325" thick.  Re. the bronze/brass bush, it might be able to be made in two parts,i.e. a plain bush and seperate washer, instead of the shoulder. I will give it some thought.