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Collection, Preservation and Display of Old Lawn Mowers

Suffolk A114: Renovation or new Engine



I'm a hobby gardener living in Germany. Love my lawn.


Unfortunately, the Suffolk A114 engine of my Atco Commodore is out of order. 

With some luck, I can make it run for a short time. But, with any ignition the engine "spits" oil (coming out of the engine) and the plug gets badly soiled.

I did show this engine to my mechanical but, he doesn't want to do the job. He said that such an old engine will make trouble all the time.


Well, what are my options now?

I'm just an office worker; don't have much experience with engine repair.

Do you think you can guide me through this renovation project via forum?

The engine is not too complicated, is it?

How much time & cost do you estimate?


What about a new engine?

Suffolk doesn't exist anymore but, are there some New Old Stock engines out there?

Or, may I use a replacement engine of an other company? I'm thinking of the Kawasaki FJ-100 which they use for the Atco Balmoral & Allett Kensington.

Does this engine fit?



Thank you


wristpin Tue, 16/08/2016

Welcome to the forum.

"such an old mower" - oh dear, I remember going to the dealer meeting when the new Commodore was introduced to the trade!

Difficult to advise at a distance but you could take the cylinder head off and check for any obvious signs of distress  such as scrapes or scores to the cylinder wall, but first check that the engine is not just overfilled with oil. If there is any obvious damage to the bore  a new or better engine is probably the way ro go. If there's no obvious damage take the valve chest cover off ( below the carburettor and exhaust) . This incorporates the crankcase breather valve which may be gummed up so give it a good swill around in petrol. Let it dry out , refit it and give the engine a run . 

If there's no improvement The choice is to strip the engine for further investigation with the possibility that it may only confirm that the problem is beyond economic repair , or to locate a replacement.

I'm not aware of any  old stock A114  engines but two places to ask are the Gateshead Mower Centre  or Jon Cruse  at the Hailsham Mower Centre.…

If you decide to fit a modern engine the first thing to check is that the crankshaft height is the same as the existing engine. I believe that it will be as your A114 was developed from a Tecumseh unit and conformed to standard dimensions.


WeedPicker Tue, 16/08/2016

Thanks for your answer,


I think, I'll give the valves job a try.

Do I have to drain oil before taking off the cover?


Anyway, I still like the idea of a new Kawasaki engine. (I don't make much friends here, eh? wink)

The Suffolk is so loud. Is the Kawasaki an improvement? Maybe even less gas consumption?

wristpin Tue, 16/08/2016

No need to drain the oil to remove and wash the breather.

The Kawasaki is actually a nice smooth little engine and if you need a mower that's ready to work when you are it will serve you well.


hillsider Tue, 16/08/2016

If the Kawasaki engine will fit your mower it will be a change for the better in my opinion and will definitely be a good way of keeping your mower in service.

As wristpin says they are a good engine.

WeedPicker Wed, 17/08/2016

There seems to be a problem with the breather.

The filter is full of oil and the valve doesn't spring back at all.


Is this a standard sized spare part?

What are the required parameters for this spare part?

wristpin Wed, 17/08/2016

When you've given the breather a good swill in petrol and let it dry it should rattle a bit when shaken. That shows that the "paxolin" disc valve is free to allow air to exhaust from the crankcase on the downward stroke of the piston and to shut and seal on the upward stroke causing a partial vacuum in the crankcase. That helps to keep the crankcase oil tight and control oil consumption.

So, check that the disc is free to move, that the breather is installed with the baffle and drain hole downwards and that the gasket between the breather and the crankcase is in position and intact.

If at some time someone has been poking around with a bit of wire between the disc and the body of the breather it is probably scrap. Good used and possibly new breathers should not be too difficult to locate as I believe they were common to several Tecumseh engines.

WeedPicker Wed, 17/08/2016

If at some time someone has been poking around with a bit of wire between the disc and the body of the breather it is probably scrap.

What do you mean by that?

As I wasn't sure if it is dirt or what, I did play a bit with the sponge filter. Tried to get it out and even pushed it in a bit.

But, I touched the disk with my finger, only.

Is it scrap now?

wristpin Wed, 17/08/2016

Probably not, but if the "fingers" behind the disc have been forced back it may  be too far back to be sucked shut when the piston rises . Some workshop manuals show the use of an L shaped wire gauge to  determine whether the gap is within specification.


WeedPicker Thu, 18/08/2016

This looks bad.

Do you see the hole and the scratch in the cylinder?

Kaput, isn't it?




hillsider Thu, 18/08/2016

Well I have seen a lot worse but all joking aside I think you need to remove the engine side cover and remove the piston from the cylinder for examination as that may complete the picture for you as it reveals its condition.The scratch on it's own does not appear to be too bad but the hole in the wall of the cylinder is rather more worrying to me for the following reasons:-

1. How deep is it and how thick is the casting at that point.

2. What has caused it.

Good luck - you are gaining experience as you investigate here even if the engine ends up as scrap.   



wristpin Thu, 18/08/2016

I've never seen a hole like that. I wonder if it was an original casting fault that went undetected during manufacture and assembly. Otherwise the bore damage doesn't look terminal but pulling the piston out  will allow measurement of the ring gaps etc.

 However before embarking on a full strip down have you tried running it since washing out the breather?


WeedPicker Fri, 19/08/2016


anybody got an idea how to get this "engine coupling assembly" off the crankshaft?

(No. 37, page 14, Commodore Manual )

BTW: What is No.38 on the same page?



However before embarking on a full strip down have you tried running it since washing out the breather?

Nope. I don't have any petrol here to clean it...

Looking at the valves I think they need a job, anyway.

hillsider Fri, 19/08/2016

Assuming that you have removed the two grub screws from the coupling body then the coupling should just slide off, they are not normally very tight on the shaft. You may need to just tap the coupling with a hammer to get it moving, At the very worst you may need to use a two legged puller to pull it off the shaft, but let us not go there until we need to.

Item 38 is a Woodruff Key, commonly called a Half Moon Key this fits into a key way machined in the crank shaft and locates in a corresponding key way in the coupling.

wristpin Fri, 19/08/2016

However before embarking on a full strip down have you tried running it since washing out the breather?

Nope. I don't have any petrol here to clean it...

No petrol in the tank from when you ran it and found that it was "spitting oil"?

Not much point in worrying about the valves until you've discovered whether with a clean and functioning breather it is still an "oil spitter".

If you really want to take the coupling off at this stage remove the set  or grub screw, squirt some penetrating fluid into the hole, leave it for at least half an hour and then carefully lever it off with two tyre levers or pry bars - taking care not to damage the crankshaft oil seal or crankcase cover..



WeedPicker Sat, 03/09/2016

Well, there are some scratches on the piston and some more in the cylinder.

I can feel them with my fingernails but I'm not sure if this really is an issue.

I don't see any damage to the rings, though.


Unfortunately, the seal for the breather did break, too...


Anyway, I looked up the dimensional specification of the Kawasaki and yes, it MIGHT fit.

At least the crankshaft should fit in size and height. But maybe it's a bit too far on the side.

Quite a risk to order an expensive engine not knowing if it fits properly.


However, Kawasaki offers that engine with the option "Reduction 2:1 gearbox".

I wouldn't need this, do I?

hortimech Sat, 03/09/2016

Those scratches don't look too bad, I have seen a lot worse and the engine still ran ok, I would be more interested in what the ring gaps are if you insert them into the bore.

You should measure the gap with the ring near the bottom, in the un-worn portion and then again about 1 inch down from the top. The first measurement will give you an idea of the ring wear and the difference between the first and second will give you an idea about the bore wear.

As for the reduction gearbox on the Kawasaki engine, you very probably don't want this. I do not know the exact engine you are referring to, but normally a 2 to 1 reduction is arrived at by extending the camshaft and taking the drive from there. in this way, either the engine runs in the 'wrong' direction or the output shaft does.



wristpin Sun, 04/09/2016


As you have now pulled the engine apart are we to assume that before you did this you did try running the engine with a fully functioning breather and that the " oil spitting" was still present?  If not, and a malfunctioning breather is the cause of the problem, any further internal work such as fitting new piston rings will be nullified by using the faulty breather.

The advice for assessing cylinder and ring wear is fine as far as it goes but it's limitation that any result is a combination of both bore and ring wear. To get a more accurate assessment of where the wear lies you really need  to check the end gaps using s new set of rings so that any variation from accepted standards is confined to the bore . That way it will become obvious as to whether new rings may solve your problem or whether  it is more serious. 

Reduction gearing whether obtained by taking the drive from the cam or from a gear train attached to the PTO side crankcase cover will not be necessary as the standard  Kawasaki will be st up to run at more or less the same speed range - 2800 to 3200 as your original Tecumseh based engine. 

hortimech Sun, 04/09/2016

Yes it would be better to test with a new set of rings, but I doubt if the OP has a new set of rings and if there isn't much wrong with the rings he has, then it would be a waste of money buying a new set.

If you look at the bottom of the bore, you will find an area that doesn't get swept by the piston and as such, doesn't ever wear. If you place a ring in this area and then check the ring gap, you will find out if the ring is serviceable. If you then move the ring up the bore and measure again, the difference between the two measurements will give an indication of the bore wear.

Of course, the only precise way of measuring bore wear is to use a bore gauge like the Baty one I have, with this, you can quickly take several measurements and find out out if the bore is worn and if so, by how much, and if it is oval etc

wristpin Sun, 04/09/2016

The problem is that there appears to be a lack of information regarding what the original ring gaps should be  and what the permissible increase is in a worn engine.

I can't find any information on any Suffolk literature other than a nominal bore size of 2.25 inches.  As the engine has Tecumseh ancestry I've tried to find a comparable Tec engine in the hope that they would be a bit more forthcoming with permissible wear and reject sizes. The nearest I can find is an H30 with a nominal bore of 2.31"  . For this the suggestion is that a ring gap of over 12 thou is a reject. However, elsewhere in the same manual the table of specifications says 7 to 17 thou.

The strange thing is that it just gives the one figure for all three rings whereas it is more usual for the compression and scraper rings to have a lower reject size than the bottom or oil control ring .For instance a similar sized Briggs and Stratton aluminium bore engine ha a reject size of 35 thou for the compression and scraper rings an 45 thou for the oil control ring. 

In the absence of any specific data for the Suffolk engine it is really a case of having an unworn ring to use to make the comparison.



hortimech Mon, 05/09/2016

What I cannot understand is where you got the idea from that the aluminium Suffolk engines were designed by Tecumseh, I was told (at the time the A98 was released) by a Qualcast/Suffolk technical guy, that it was an in house design. The design only really came about because the cast iron plant they were using to make the old engines was condemned as unsafe and it was cheaper to make a new engine.

If you look at the first alloy Suffolk engines, they were basically a B&S look alike block with the 98cc cast-iron flywheel, carb etc bolted to it.


wristpin Mon, 05/09/2016

Could be wrong but our information back in the day was that the  original cast iron Suffolk engine was made under licence from  BS  and the A98 under licence from Tecumseh.  The same was said about the A114.

With the various changes of ownership of Suffolk - Blue Circle and Bosch etc it is quite probable that  that many of the original records have disappeared so it may remain a mystery . 

hortimech Mon, 05/09/2016

Yes, the cast iron Suffolk was based on a B&S design, I was told they bought the design, but you could be right, they could have licenced it.

As for the A98, the short block looks nothing like a Tecumseh product, it looks more like a B&S one, and as I say, I was told by a Suffolk technical person, they designed it (in a rush) in house. I think they took the cast iron engine and looked at a Briggs and replaced the cast iron bits with alloy.

There was a manual for the A98, I say manual, it was a poster you could fold up into A5 size.

The later A114 was just an oversize A98 with a different carb, it seemed that the design kept changing for the worse.


WeedPicker Thu, 08/09/2016

Wow, nice poster.



No, I didn't try with the with the cleaned breather.

The breathers gasket broke and I wanted to look at the cylinder before buying new stuff.