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Collection, Preservation and Display of Old Lawn Mowers

30" Flail mower

Hello i am in need of a cyclinder head for this mower it is a 30" Flail mower powered by a MAG Motasacoche SA Geneve Switzerland petrol engine i have been told it is about 9 or 10hp


I have just got this from ebay and on getting it home i found the last owner has ripped the plug threads out of head. I know i can helicoil the plug hole to put the threads back in to it at a push.  But if it goes wrong i would like to have a spare head at hand as a fall back as to say.

If any one has one they would like to sell i would be most interested or if they know where i could most likley find one for sale.





hillsider Tue, 25/06/2013

Hello, that looks a beast of a mower! Re parts for the engine I have used Meetens Engines for MAG spares without problem in the past so give them a call. The problem with the existing cylinder head should be repairable successfully using a thread repair kit such as a Helicoil so long as the plug hole has not been damaged enough to over size it past the tapping size for the new insert. I have seen aluminium castings fitted with thread inserts from new to provide greater strength and reliability so there should be no problem with a plug thread once installed correctly. Ray.

wristpin Tue, 25/06/2013

That's a Ransomes pedestrian flail. We had one in the 80s and used to hire it out with an operator for "taming" overgrown gardens - particularly if we had just sold a new ride on to new occupants and wanted to avoid them doing in the belts on the first outing! Despite its macho looks it was never quite the jungle buster that its appearance suggested.

Memorable outings with our machine included hitting a 5 litre tin of whit emulsion paint and winding a length of wire netting round the rotor! Happy days!

Widow Maker Tue, 25/06/2013

Yes a helicoil was my thoughts to but the plug looks to have been shot out of head maybe when it was last run by it's late owner. As it is the plug just sits in it's hole with no way to tighen it up so i would say it is an over sized hole. the only other way is to see if i can get hole welded up to a smalled size and re tap it to the plug size or helicoil size, the other way is to replace head with another head. I have looked on ebay for parts but there is nothing listed on there for it.


But once i get over this plug hole issue i would think it would be a great mower to have for a bit of fun.


wristpin Tue, 25/06/2013

Don't give up on Helicoiling without checking first as the o/s tap to create the thread for the insert takes our quite a bit of metal. At a guess at least 2mm so it may well recover the situation without the need for welding.

There is another alternative which will almost certainly do the job and that is a threaded bush or sleeve - can't remember their proper/trade name but they are on the interweb/ fleabay.Assuming that you are not contemplating purchasing the Helicoil kit your self (about £70 for a 14mm plug size) and that you are going to take the head to a machine shop/engine reconditioners you can take their advice on a no cure no charge basis.

hillsider Tue, 25/06/2013

As wristpin has stated don't give up on the thread repair just yet, you may well find that the tapping drill for the helicoil will clean out the hole further and still allow a good repair. Unless you are planning to use it more than once thread repair kits can seem pricey but balance that against the costs of an engineering company doing the work or a new head if you find one.

Widow Maker Thu, 04/07/2013

Thanks guys for your support i have solved the issue i have managed to rethread plug the hole with a larger tap and made an insert to screw into it with the correct plug thread size it has taken some doing but looks like a good fix if i have any issues i will post what they was. But it has done the same job as the kit on ebay. if this fix fails i will have to weld the plug hole up so i can have another go at it.

I have taken photo's i will upload them as soon as i get my workshop laptop back from pc shop next week.

Widow Maker Thu, 01/08/2013

Hi i have got the plug tool from ebay tomorroow i am going to sort it out i have removed the head from engine so not to get any bits in the bore.

I do have another question about the ignition on this engine. From what i can see it looks as if it has two coils inside the fly wheel one being the ignition coil and the other looks like a charge coil. Does this setup need to be run with a battery or does it not need a battery. I only ask this as it looks like someone has been messing with the wiring there is a connector block at back of the engine and as of yet i have failed to get a spark. The flywheel is welded on and i will need a bigger and better puller to get it off, i have managed to clean the points through the tiny little hole someone put there as an after thought.


hortimech Fri, 02/08/2013

Hi, ignore the second coil, it is, as you thought, a charging coil and no you do not need a battery.

Also, DO NOT attempt to remove the flywheel with a two or three legged puller, it is not welded on. If you look carefully at the center where the retaining nut is, you will see that the hole is threaded internally, to remove the flywheel you slacken the retaining nut then screw a removal tool into this thread and then tighten a bolt that it screwed into the removal tool, this bolt presses on the end of the crankshaft and pops the flywheel off the taper, although you mostly have to give it a rap with a hammer to shock it off.


Widow Maker Fri, 02/08/2013

when i said welded on ment it is not willing to move, i have looked in the center but i do not see any threads there. i have made a puller bracket that i have bolted to the recoil drive bolt holesso have something to pull on from the center. As the flywheel is made of a cast metal i thought it was best not to pull from the outer rim of it as it would more than likely break. i have managed to get a spark from the coil by arcing the ingion kill wire to ground this made a spark at the plug. i have cleaned to points and gapped them but they seem to doing nothing so as a guess i think there is a wire issue inside the flywheel to the points. The cut outs in the flywheel are to small to see the wiring i need to get to so the flywheel needs to come off to sort it now.

wristpin Fri, 02/08/2013

Is there an ID plate on the engine cowling, guess that it may be an MAG 1040-SRL . If you know which engine it has I may be able to find you a wiring diagram but from memory the engine may have a lighting/charging coil even though not used on that machine so the exterior terminal block is a bit misleading and I think that if you have a spark it is unlikely that you have grounded the kill wire!

I was a bit surprised at Hortimech's description of the puller required to remove the flywheel as I can only remember MAGs as having an 8mm tapped drilling either side of the flywheel nut to accept 8mm screws  through a bar bearing on the slackened flywheel retaining nut. Holes are nice and close to the centre with no danger of pulling the flywheel rim off the centre boss. I still have such a weapon in my tool box. Still, time passes but H's description fits a JLO puller exactly!

hortimech Sat, 03/08/2013

That could be because if you remove the big thing with all the fins on it from the flywheel, underneath it is the same flywheel as a JLO engine.

wristpin Sat, 03/08/2013

That is interesting. I have dug out some old MAG manuals and if we take the 1045 as an example, the manual marked edition 1(1969)  shows a flywheel with drilled holes as I have described but edition 2(1972) shows the JLO type (Bosch?) flywheel as you have described it. Still got a puller for the JLO type too.. Also a dummy cam so that the points could be cleaned and reset  with the flywheel removed so as to avoid having to struggle though the "port hole"  !

Widow Maker Tue, 06/08/2013

i have managed to remove the flywheel and the issue was down to a faulty set of points where the spring is rivited to the points it had a bad connection there so i cleaned it up and soldiered it this fixed the issue.

how ever i have a more pressing issue after it put it alltogether with new plug hole fitted and now having a spark. i changed the oil as it was very dirty as i did so i noticed lot of metal in the oil. when i ran the engine it fired up with very little effort bad i found where the metal had come as i could hear the big end knocking.

so it now looks like a rebuild or a replacment engine is needed.

Widow Maker Tue, 06/08/2013

The fins are part of the flywheel, but i have managed to make a puller up using the two bolt holes that hold the recoil adptor on to the flywheel. once i put puller in there it came off with little effort.

wristpin Tue, 06/08/2013

Have you a positive ID on the engine , ****-SRL etc?  Most MAGs had replaceable big end shell bearings so it will be worth checking out the extent of the damage. Once you know what engine you have and the extent of the damage have a word with Paul at Meetens - things may not be as bad as you think.

Widow Maker Wed, 07/08/2013

Not sure what model engine it is as the tags have been painted over at some point in it's life. tomorrow i am on a mission to remove some of the paint to find out what it is. i have emailed a member about spare parts that they are selling here on the old mower club and i am now a waiting a reply from them. if that fails i will lift engine from mower and start pulling it down to see how bad it is it is a little smokey also so i will replace the rings at same time as i have had head off to repair plug hole the bore did not look damaged or badly worn so i think i would get away with a set of ring in there.

Widow Maker Wed, 07/08/2013

they are not good the tap is badly ground un even had to use a tap of my own. To fit the coil i removed the washer from an old plug and screwed the coil on to it. I then dropped them both in the deep freeze for a few hours and left the head in a window in the sun to heat up. After a few hours it was time to screw that cheap coil in and little oil and away i went nice and slowly it went in until it got just over half way and it snapped the coil off. i had to pick the broken coil out that was not much fun. I run my tap back down the thread hole and used one of the shorter coils this has gone in all the way using the same method as i used for the longer coil. So yes that kit does work but it is major cheap quality and i do advise taking great care with it and not using the tap that comes with it as it is utter rubbish and would of wrecked any chance of repair at the users exspence. The coils are poor quality but the theards are cut much better that the tap suppied in the kit.


Widow Maker Mon, 26/08/2013

I have pulled the engine down in to parts to see what damage has been done, to be honest it looks not to bad. There is no play in the bigend shells or in the little end, how ever there is alot of space in the bore that could be the noise i hear when it is running. What i am planing to do is replace the shells piston and rings and the little end bush the bore i will get sized up first before parts are ordered but the shells are still the std set in there the piston looks to have been repolaced at some point as there is no std stamp on it that i can see. So i will now have a clean up and measure the piston to find it's size i might end up having a re-born at last resort. What i now need is a workshop manual on the engine if anyone can help with that please it would now be of great use to me more than anything else.

engine type i have now it is a


1045SRL X155

CC 450

Bore 88

Stroke 74

RPM 3000


wristpin Tue, 27/08/2013

I've got a Mag publication titled Workshop Manual  and had a quick look through it last night with a view to copying and sending you the useful pages but amazed to not find much reconditioning info such as available o/s pistons and rings. You said that the engine was knocking but now have not found any obvious big end wear etc. Are you sure that your knock was not down to excessive carbon build up on the piston crown or in the head? Another possibility is an incorrect or "over compressed" head gasket.

One of the best souces of Mag information will be Paul at Meetens.

janbo Sat, 31/08/2013
Hello am new to this forum, live in Holland and have some experience with Ransomes lawn mowers.


Regarding Mag 1045 of pedestrian flail,    Cylinder bores are as follows:

         Standard:        88.00 m       (+0.015 -0 mm) Piston pt  nr: 1.9020.220 (assy)

         first oversize:  88.30 mm        same tolerance.        ,,  1.9020.221    ,,

        second overs.:88.60 mm        same tolerance         ,,   1.9020.222    ,,

        Third overs.   : 89.00 mm        same tolerance         ,,    1.9020.224     ,,    


 Crankshaft big end size: 

       Standard                  34.90 mm   ( +0   - 0.013mm) 

      first u.size                  34.65 mm                                            

       second u.size          34.40 mm       All same tolerance      

      third u.size                 34.15 mm                                              

      fourth  u.size               33.90 mm                                               

Hope you can find parts , did a Mag 1026  overhaul in 2001 and had to fit a piston of a Toyota Corolla , various other engine parts taken from Gutbrod engine. Gutbrod made Mag engines under licence .

Regards    Jan.

Widow Maker Wed, 28/08/2013

I must say i have everything i now need to measure up to try and solve this knock from the bottom end. I have set the rod up to see if it is twisted as there is wear on one side at top and wear at bottom but on the other side of rod. I have a feeling this could be part of the issue. As for carbon in head i have had head off for plug hole repair and it was de-coked. I have found a tiny little bit of play in the little end but nothing that would make the noise i hear when the engine is runing at tick over speed you can hear the knock but at as loud as it is if you bring the rpm up a little.


Widow Maker Wed, 28/08/2013

Great thank you so much this is just what i needed and jan sent me some sizes to go off this will help alot also as it is i was working with sizes the could be wrong due to wear.

I will let you know in a few days the out come of what i find, i have emailed paul two days ago i will phone him in a few days when i know what parts i will need to repair this engine with.

wristpin Wed, 28/08/2013

Just a thought, it is an engine knock that you are hearing? From memory* that machine has a centrifugal clutch as on the Mastiffs etc and they can knock; but that type of knock should disappear as the revs are increased and the clutch becomes fully engaged.

* can't lay my hands on any literature to confirm that at present.


Widow Maker Tue, 01/12/2020

After many hrs of pulling it down to parts the out come was it was at end of life. The bore was very badly worn in the mid section it was so bad that most of the compression was leaking bad in to crank case and blowing oil out of the breather, this I would think is how the mains had become damaged. 
how ever someone had been in there before me and inserted a new piston and conrod witch was oversized to +10. I did ohm the bore before putting it back together, I've got the engine still in garage it does run but bottom end is noisy. As for the mower I put a lister diesel on it type aa1 the new drive pulley cost best part of £550 to match the mowers drive belt set up. The engine I mounted on a 20mm tick plate that I mounted on cotton real engine mounts so the engine did not shake the mower to bits. It turned out very well in the end. 

hdtrust Wed, 02/12/2020

Yes still looking for photos!

From the early pictures you sent of the flail,there appears to be something else missing,on the front of the machine there should be 2 lines to demark gradients of which the flail can work safely.This is extremely important on that machine.I use to work them in the early 80's.We had a major inquiry from the Health and Safety Executive,over a seriously bad accident while working on gradients,with Sheffield Recreation Dept.

I'm afraid that Ransomes machine,was not one of the best on the market,Turner was alittle better.

When using flails,its so important,not to use warn out or old machines due to their nature,but if you are content with old,one of the best was Brott.The best present flail on the market is made by BCS with a handsome price tag to go with it!

I use the latter commercially,never looked back (but when I do,it mulches all the debris extremely fine)

By the way although it does not matter now,but your original engine,the MAG was also fitted to the Ransomes Reelcut 2000.

Kind regards