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Collection, Preservation and Display of Old Lawn Mowers

Qualcast 35 S Strange problem

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Dear Experts,

I have an up until the end of last mowing season excellent running Qualcast 35s with Tecumseh 5148 or maybe 6148 Carburettor. After starting well all season suddenly it needed the Choke left fully on all the time to run correctly. If I even click the Choke back 1 click it will stop running, so I have to start it with the Choke full on and leave it like so to keep it going. I distinctly remember in the recent past accidentely forgetting to back the choke off after starting, and the lawn mower would have stopped until I clicked the Choke right back to totally off. A while back, I had to replace a very badly dozed Carburettor bowl Rubber O Ring (the big one) as the mower suddenly at the start of the new season was very difficult to start. I have just ordered from JAPG a new Float needle/spring/seal assembly in case the inlet is not shutting off as the carb bowl fills with petrol, I have also ordered a new Sponge Filter and Spark Plug as I read somewhere that these should be replaced every 2 years, the Foam Air Cleaner I have removed is very badly dozed and quite filthy and decomposing. Is there anything else I need to check please as this Choke having to be left on all the time happened suddenly it was not gradual. Many thanks Paul

Forums

wristpin Tue, 25/02/2020

Other than the air filter you probably don’t need any new parts but what the machine does need is a very thorough carburettor clean - preferably in an ultrasonic cleaning tank.

RIPMAXRAPIER Thu, 27/02/2020

Angus,

Thanks for your help, you helped me before with an old Suffolk Super Punch 14" a couple of years back and got it going very nicely. I will do as you suggest and also fit a new Air Cleaner Foam as the existing one is decomposing. The Spark Plug is an old NGK donkeys years old, as the lawnmower is 20 years old and my late dad probably never had it replaced. The Lawnmower is in terrific condition for its age, almost like new.

My old Suffolk Punch now needs a new Fuel Tank as the existing tank is rusted internally and every year at the start of the season I have to de-gunge the Zenith 13 TC Carburettor , as it is full of rust particles. I have bought a new 1 litre plastic tank from Japan and I will be fitting it over the next few weeks to solve this issue once and for all, it wont look right but it will stop the old rotten tank from polluting the carburettor.

Many thanks for your much valued assistance.

wristpin Fri, 28/02/2020

Why not just derust  the existing one or  fit an in-line filter to catch the crud before it gets to where it can cause a problem ?

RIPMAXRAPIER Thu, 09/04/2020

Angus,

The bottom of the old fuel tank is so rotten it is seeping petrol all the time and it would need a tin basher to cut the bottom of the tank out and weld on a new bottom, apart from the base the rest of the inside of the old fueltank looks mint, so I have kept it just in case I decide to have it properly repaired, I have just stripped the whole Suffolk Super Punch 14" mower which is 54 years old and I have buffed everything to the bare metal and cleaned, Primed and sprayed everything. I am also replacing all the bolts with brand new. The Engine Mount bolts are 8mm but the small bolts that secure the Engine Cover are not 6mm,  I suspect maybe 1/4"  BSF can you confirm the size and thread please so that I can purchase 5 nice shiny new Hex head bolts. I am also painting the blades the original colour. Will send you before and after photos when completed. I decided to do this project as a Coronavirus Lock In project to keep me sane in my recent retirement. I gave the mower a lick of paint a couple of years ago but it was all starting to rust again. Many Thanks Paul

wristpin Thu, 09/04/2020

A lack of any images makes it guess work but unlikely to be BSF, more likely UNF  or UNC ,  UNF If going into captive or rivnuts or  UNC if going into a casting.

Unless the machine has been re-engined I can’t equate Tecumseh with the stated age, or am I getting confused between two different machines ?

Fuel tank . Probably  better ones to be had for less money than surgery, unless you or a friend have the ology and kit.

A picture replaces a thousand words!

 

RIPMAXRAPIER Fri, 10/04/2020

Angus,

The Tecumseh is on my now working great Qualcast 35S QX. The questions on bolt thread relate to my 54 years old Suffolk Super Punch. The Hex head bolts screw the Engine Cover to the actual Engine Casting. I thought they were 6mm metric but when I try a 6mm bolt it just starts to screw in and then locks so I know it is a non metric thread. I will assume that the fact they screw in to the Engine Casting means they are UNC. I will enclose a couple of photos later. The Mower Engine casting is a Type 75G-14  Model 28A. Many Thanks Paul

RIPMAXRAPIER Sun, 12/04/2020

Hi Angus,

Can you possibly measure the height and width of the Suffolk Super Punch Chain Guard Decal. I am having one made and the guy needs the dimensions.

The bolts are UNC as you suspected 1/4" UNC X 1/2" Long, I will order a pack of 5.

 

Thanks

Paul

RIPMAXRAPIER Mon, 13/04/2020

Angus, Du you even know anybody else with one. See attached BEFORE pictures of the Suffolk Super Punch I am presently renovating. Regards Paul

RIPMAXRAPIER Wed, 27/05/2020

Angus,

 

Trying to upload the BEFORE RENOVATION photos again, for some reason they did not move from the ipad.

Regards

Paul

wristpin Sun, 12/04/2020

Pity about the missing pics as I think that I may have misunderstood the age of the machine the you have. Are you pressing the insert button?

hortimech Sun, 12/04/2020

Yes, it totally depends on which Suffolk Super Punch it is, the Cast iron one, the aluminium one, or the latter one that was really an Atco painted red.

RIPMAXRAPIER Sun, 12/04/2020

Angus,

Yes I am pressing the Insert, if you click on EDIT they can be viewed no problem

RIPMAXRAPIER Sun, 12/04/2020

Hi Hortimech,

It is the Cast Iron Engine and Aluminium Cast Side Plates, I believe about 1965 or thereabouts.

 

Thanks

Paul  (RIPMAXRAPIER)

wristpin Sun, 12/04/2020

OK, it is what I originally thought. There’s a guy in Australia who regularly advertises Suffolk Decals   - May be worth a look.

RIPMAXRAPIER Mon, 13/04/2020

Hi Angus,

Yes I have already looked at him but he actually only advertises the Decal for the Grass Box and it is 210mm x 185mm. It is the same decal the guy is making for me, but he wanted the exact sizes. He is called Vintagedecals.com solution2print@yahoo.co.uk and his Lawnmower decals are excellent ,as he has already supplied a Clutch Guard decal and a new Engine casing decal ( the one listing the lubricants and engine details) but he has no Chain Guard Decals. I am also getting an Aluminium Weld done using a TIG Welder after hitting a buried rock when cutting my sister in law's grass for her ( her husband died with Oesophegal Cancer and I help her out by keeping her grass cut for her) and the base of the chain guard struck the rock with me at full speed, and the mower jumped up and the Chain Guard fell off, the flange which the Chain Guard Bolt screws in to is welded to the side casing and had sheared off. There was only a small piece of rock sticking up in the long grass, I thought I would use the corner of a spade to lever it out BUT but when I finally got the rock dug out it was 18" round and I had trouble getting it out of the hole !!! Small wonder it damaged the bolt flange????

wristpin Mon, 13/04/2020

Back in the day that boss / flange injury was quite a common occurrence and TIG welders were not so common , Central Spares sold a repair kit that would get one out of trouble without welding. It consisted of a large top hat bush that pushed through from inside the chassis side frame together with an over length screw. A bit of a fiddle but more cost / time effective for s busy workshop than fiddling around with studding and penny washers.

Chris G Mon, 13/04/2020

I did that repair in a similar way but think I used 2 opposing nuts/split washers to clamp up on the chassis and some threaded bar.It was a little while back..

You can get threaded top hat "bungs" for £4-5 off ebay which may need some cutting back depending on length but a nicer solution.

 

RIPMAXRAPIER Tue, 14/04/2020

Angus,

Sounds like a cunning plan if TIG doesn't work out may thanks for the info.

Paul

RIPMAXRAPIER Tue, 14/04/2020

Chris,

I get exactly what you are talking about and thanks for the suggestion, I was gutted when this happened, as I was doing somebody a good turn and the bit of rock which hit the base of the Chain Cover Plate was hidden by long grass when I struck it, it turned out to be about 18" diameter, and luckily after nearly giving myself a Hernia trying to crowbar it out,  a guy 2 Holiday Homes down from us was using a Mini Digger, and he came up with a small bucket and coaxed it out and also took it away and brought me some soil to fill the hole

RIPMAXRAPIER Wed, 15/04/2020

Chris,

I found the Top Hat Bung and if only the hole left had been less than 12mm it would have been a solution without the TIG Weld. Unfortunately the hole in the side casting of my Punch is about 20mm and the Bung is only 12mm dia.

I suppose I could get a bespoke bung made with the major Diameter 30mm if it comes to that.

Thanks for the info. Paul

Chris G Wed, 15/04/2020

Hi Paul, Ouch! that's alike big hole, and maybe a bit  irregular? 

Probably a bodge on a bodge too far, but a big M12 washer with outer dia of 34mm like this https://www.ebay.co.uk/itm/FORM-G-WASHERS-M12-12mm-LARGE-FLAT-WIDE-THICK-METRIC-BRIGHT-ZINC-PLATED/174138818876?hash=item288b7b813c:m:mNDbmaLFvkbc60e35kDy8-w either side of the top hat and case might work, but too much fiddling about with lots of loose metal to bolt up and probably tricky to line up the rod with the outer cover hole...

I have a small lathe but my screw cutting abilities are non existent, a friendly machine shop could knock you something bespoke up for not a lot I would have thought, but you may need to get it all apart and step drill very carefully to get a clean round hole if its a bit of a mess..

Good luck, let us know how you get on.

hortimech Wed, 15/04/2020

I used to repair these quite regularly using a piece of flat bar, approx 1/8 X 1 x 3 inch (sorry, never really been metricated). Mark for a hole in the centre and another two either side of this, approx 1 inch away from the centre, Drill holes, the centre one has to be clearance for the cover retaining screw (5/16 ?) and the other two clearance for 1/4 inch, Weld a nut over the centre hole (obviously one that the cover screw fits), then centre the bar over the hole in the sideplate and drill two holes to match the holes in the bar. Remove delivery plate and fit two bolts through the holes you have just drilled and the holes in the bar, retain with spring washers & nuts. Fit cover and retaining screw to get an invisible repair

RIPMAXRAPIER Mon, 18/05/2020

Angus,

New Air Cleaner Sponge element and spark plug fitted to the Qualcast 35S QX, also complete carburettor clean out using Comma Carb Cleaner. No access to Ultrasonic Bath unfortunately.

Carb built up again and connected fuel pipe. Put the Choke on, pulled the starter cord and started first time exactly like it used to be where you need to immediately take the choke off as soon as it starts, so that's great. Thanks for your help.

Just for info, the old 54 year old Suffolk Super Punch 14" casing is now at Ashgrove Engineering having the sheared Chain Cover nut TIG Welded back on, there is a guy there who can weld anything as he used to work for Rory Woolff Engineering, Rory was a big mate of the late Fred Dibnah, Fred was heavily in to Steam Traction stuff and so was Rory, I was a very big fan of Fred Dibnah myself, a marvellous guy. Hopefully I will have the old Suffolk Super Punch fully built up and engine started soon, new Oil filled , new spark Plug fitted and new Air Cleaner sponge element fitted, also cleaned points while it was stripped and lubricated the small felt pad that lubes the Cam with 3 in 1 and coated the cam very lightly with Silicone Grease. Checked valves and lift gaps and all ok, hopefully it will start like the Qualcast !!!!!!  Will send you some Pictures of the finished job, new decals and all. The green spray paint I obtained is a bit lighter than the John Deere green, but I think it looks quite cool. Many thanks Paul

RIPMAXRAPIER Wed, 20/05/2020

Chris,

Picked up the mower chassis today with the Chain Guard Nut successfully TIG Welded back exactly as it was, very pleased as it keeps everything original. Hopefully I can now start building the whole thing back together, as all that was holding me back was getting this TIG Weld done, as I was able to keep the mower bottom assembly easily transportable and a lot lighter than having the engine back on, also if the engine had been  back on and the welder turned the mower on its side to weld, it could have resulted in an oily puddle on the floor of my brand new oil fill. Engine is complete and ready to bolt back on, I am hoping to get some nice new Cadmium plated bolts and bright washers to build everything back up, just awkward at the minute as our local fixing supplier is shut because of the lockdown, but maybe he will be open again tomorrow

RIPMAXRAPIER Wed, 20/05/2020

Hortimech,

Thanks for your options advice.

I picked up the mower chassis today with the Chain Guard Nut successfully TIG Welded back exactly as it was, very pleased as it keeps everything original. Hopefully I can now start building the whole thing back together, as all that was holding me back was getting this TIG Weld done, as I was able to keep the mower bottom assembly easily transportable and a lot lighter than having the engine back on, also if the engine had been  back on and the welder turned the mower on its side to weld, it could have resulted in an oily puddle on the floor of my brand new oil fill. Engine is complete and ready to bolt back on, I am hoping to get some nice new Cadmium plated bolts and bright washers to build everything back up, just awkward at the minute as our local fixing supplier is shut because of the lockdown, but maybe he will be open again tomorrow

Chris G Tue, 26/05/2020

Paul, well done on the "proper" repair! Assume that was a bit more than a few beer tokens to clean up, position and tig the boss back. Look forward to seeing the rebuild, in fact the TIG job would be nice to see. 

Cadmium plated bots! very flash yes

RIPMAXRAPIER Fri, 12/06/2020

Need to remove the Flywheel as with the points fully open I am only reading 1.1 Ohms across the points ,so maybe why I have no spark at the plug. I suspect the Condenser could be nearly dead short or something else is shorting across the points, they are clean and 20 thou gapped and I have tested the Magneto Coil Secondary 3.5 K Ohms which is normal and also fitted a new Spark Plug HT Cap as the original had a break between the Carbon slider and the spring so I was reading Infinity Ohms from the Screw in end thread to the spark plug toucher. What is the usual expected value of the Primary Coil on the Magneto please, as the 0.8 Ohms extra above my test lead resistance of 0.3 Ohms giving my 1.1 Ohms Reading could be the Primary, though I expected 10 to 20 Ohms Primary Coil resistance. My Test Meter is a very accurate calibrated Fluke Model 29, so the readings I have quoted will be pretty exact

Chris G Sat, 13/06/2020

 I suspect the Condenser could be nearly dead short or something else is shorting across the points,

Paul, did you manage to answer your own question? and do post up some images of your finished project - lookes very good.

RIPMAXRAPIER Sat, 13/06/2020

Chris, Not yet I have opened it as a new topic, For some reason I cannot upload the photos and I know I am doing it correctly. Appreciate all your help.If I had this points issue sorted it will run OK.

RIPMAXRAPIER Mon, 15/06/2020

Chris,

Having another go at uploading the photos.

RIPMAXRAPIER Sat, 13/06/2020

Chris,

 

The part about the Primary winding resistance - Yes I am pretty sure it is about 1 Ohm. As to why my points are intermittently not shorting the Primary Winding to earth to cause the Swell and collapse of the magnetic field in the Magneto to induce the field in to the Secondary to produce the HT from the Secondary - Still open for suggestion as the points are clean and touching but not actively shorting the primary to ground once per revolution to allow the creation of HT.

I really want to remove the points to check everything and I need to know if they can be carefully removed thro the Flywheel Aperture, or do I need to pull the Flywheel off to access the points. I had a really strong spark for about 5 revs of the flywheel turning it by hand, then the HT stopped again and when I tested the points again I had the same initial problem of not shorting the Primary coil of the Magneto to ground one time per revolution. Either that or it is a dodgy Condenser. 

Prior to my recent renovation,  last year I was having intermittent starting issues with no spark, but if you just kept pulling eventually the engine started and ran well, maybe the Condenser has been iffy for some time as it is 54 years old and the electrolyte could be drying out. It is a 0.2 uF Condenser, do you know if the correct one for this Suffolk engine can still be obtained ??

Many thanks

wristpin Sun, 14/06/2020

Never tried key hole surgery, take the flywheel off and do the job properly. Check that the points are truly clean and shutting squarely. Condensers of almost the right dimensions can still be found but beware of some new old stock on that auction site, some have been new for too long.  A Meco type trigger module will replace both the points and condenser for very little more than the cost of both.