Trusty Suffolk Punch (Mower) Poorly

[Robotstar5]

They are inclined to the flywheel key letting go, this would account for the peculiar feel when you try to pull start it too. I had a cast iron Suffolk which did this, made a right mess of the keyway too.

It's pretty straightforward to have a look, from memory it's 4 bolts and 2 nuts to remove the cowling then a L/H threaded nut holding the flywheel

As the flywheel is keyed you don't have to worry about resetting the timing like Villiers engines

Close up of the key

 

[Neilj]

Have you got a spark? Dodgy points / condenser or a failed magneto coil (I think that's what they have?) sound possibilities if it was sudden stop and won't give any hint of starting.

 

[julianthegypsy]

These are prone to leaking exhaust valves. The valves get tighter in use. Take the side cover off and get a feeler gauge in. The cure is to grind a bit off the end of the valve. Fairly easy to do and it should run a treat for years after it's done.

 

[Ross365]

Testing.....Oh way to go! For some reason, I could not post anything on this thread on Sunday; mods think a server problem.

Had the flywheel off and the key and the points all look fine.

Not quite sure where this takes me...valves???

 

[julianthegypsy]

Are you getting a spark?

 

[Fred Trevvett]

Very long shot but I assume the threads of the spark plug are clean?

 

[octo0072000]

iv'e got a engine in the shed was running when removed from the mower any good for you collect from Doncaster FOC

 

[Ross365]

Yes, there is a spark at the plug. I keep two plugs so one is always clean to put it; it does run a bit rich, but has done for 30 years. The thing about the plugs, is that it had started up, was running smoothly with no hesitation and then stopped in an instant - and hasn't started since. Never had it do that before.

I'll clean and set the points and put it back together. I'll do a compression check. I ordered some Easy Start to play with and also ordered a head gasket if I have to look at valves.

@octo0072000 many thanks for that offer; let me get back to you later.

The mower will have to go to one side for a day or two as my 24 year old Rover 620 has its MoT this week. I changed the rear discs for this one (they may have been originals) and had a "bit of rust" over the inner and out disc areas

 

[julianthegypsy]

Oddly, if the valves get too tight on those, the plug gets clogged up just as you'd expect if it was running rich. Basic carb setting is full in and a quarter turn back on idle jet and Three quarters back on main, if it helps.

 

[octo0072000]

Yes, there is a spark at the plug. I keep two plugs so one is always clean to put it; it does run a bit rich, but has done for 30 years. The thing about the plugs, is that it had started up, was running smoothly with no hesitation and then stopped in an instant - and hasn't started since. Never had it do that before.

I'll clean and set the points and put it back together. I'll do a compression check. I ordered some Easy Start to play with and also ordered a head gasket if I have to look at valves.

@octo0072000 many thanks for that offer; let me get back to you later.

The mower will have to go to one side for a day or two as my 24 year old Rover 620 has its MoT this week. I changed the rear discs for this one (they may have been originals) and had a "bit of rust" over the inner and out disc areas

620 front discs are a pain to change rears not so much
my last rover was a diesel 45 Connoisseur prior 600 1.8 petrol

 

[Ross365]

So, I finally got around to stripping this engine down. Initially, I couldn't really see anything wrong, other than a lot of soot on the head and the exhaust valve stem. So starting to re-assemble, and at that point I realised the exhaust valve stem is a very sloppy fit in the guide; I reckon there's the best part of 1mm wobble. The inlet valve is not a close fit but not as sloppy.

Looking at the design of these engines with their "oil mist lubrication" system, I really cannot see that much oil could ever get up towards the valve stems and guides. I'm guessing that this engine is ~40 years (or more) old; I bought it second hand 30 years ago. The piston / cylinder seem fine as do the con-rod bearings, crankshaft and camshaft.

This is unchartered territory for me. Has anyone got any experience of this and /or the prospect and cost of replacing the guides on this old engine?
Generally, parts are getting hard to get, apart from one or two old guys who have been doing mowers for decades.

 

[Robotstar5]

Try Jonathan at the Mower Centre for spares.

 

[merryman]

Doubt if it has guides, most just run in the cast iron, and valves slop about on old side valve mower engines anyway. Suffolk/Qualcast stopped making the cast iron side valve engine in the early 1970s, and replaced it with an aluminium version, which is generally regarded as not as reliable, and rattled from new. There are still lots of both types mowing lawns, all over the country. Strange you haven't found a reason for it stopping, or the unusual "feel" of the starter.

 

[Ross365]

@Robobstar; thanks for suggesting Jonathan, but he is one of the people I already had under my "old boys"; bought a few things from him, and he's always good.

@ merryman; I'm pretty sure it does have guides, and certainly they are shown in the service manual, parts 16 and 17. They definitely look different from the casting of the block

The picture is from the manual for the Super Punch (17" cutter) like mine. I agree, I still don't understand why it stopped like it did, and the subsequent pattern of events. But it certainly did need a de-coke.



On YouTube, there is a guy who's posted 3 videos on dismantling/rebuilding the engine (he's dealt with the number of them)

. He notes that on the majority of engines he has worked on, the spring that holds down the breather valve has been removed. I wonder if this has been done to improve the access of oil mist to the valve chest?

There isn't much need to mow the lawn at the moment , so I can take my time with this. Although the ex valve is wobbly at the top, it still has a good fit at the bottom where it sees the cam followers (and gets more oil mist), so I think there's some life left in it. I've had it 30 years, so I very much want to keep it going.

 

[slim_boy_fat]

There isn't much need to mow the lawn at the moment

You can have mine, then - it's growing like mad.....

 

[slim_boy_fat]

You can have mine, then - it's growing like mad.....

Here it is as it's in the process of getting a haircut. Cut last weekend and I've had to remove 2 x spacers from the Flymo for today's cut. Couple of days, spacers replaced and it'll get done again.

 

[Ross365]

I'm pretty certain that if a took a match to mine, apart from the fact it's a bit short, that it would burn nicely

 

[Highway_Star]

I've had a bit of experience with these. I am still cutting our lawn with one that was bought by my grandfather in the mid 1960s. In the 1980s when he passed it came North to us, with a siezed engine and a cracked roller. My dad and I overhauled the engine one summer holiday, a colleague of his in the dockyard brazed the roller back together. Sometime in the early 2000s it stopped dead and got put away.
A valve lap, carb overhaul, proper service and a new condensor. Away it goes and still is.
The book does recomend running the enging until warm a few times over winter.
I have the original manual scanned, if that helps?

 

[Migmac]

I’ve just recently had a Honda engine stop all of a sudden and wouldn’t start up. It had been in use a few days before and had given no indication there was a problem. It was a fuel problem, carb cleaner squirted into the carb and it ran. WD 40 isn’t a good starter fluid. Anyhow a new carb was put on as a carb kit was only slightly cheaper when you work in the hourly rate. I stripped the old carb and it was full of what i can only describe as damp brown sugar. I’d be stripping the carb down