The only thing left to do now on my 1935 (Thanks Clive, for setting me straight on the year) Atco 14" is a load trial now to ensure the mower can function/perform under load, which might be this Saturday, I don't know, we'll see. I'll take some video of it (if it performs!).
That being said, the next mower up on my bench is a 1954 Atco 14" (I'm pretty sure about the year, the machine no. is 1454 NME), primarily because under load in my back garden it kept stalling on me, and this was the result of something getting jammed or bound up somewhere in the drivetrain from the motor to the cylinder cutter.
At the initial run up, I ruled out the clutch on the motor as I couldn't find any signs of binding. On Tuesday I swapped out my 1935 Atco for the '54 Atco on the service trolley, then truly struggled to get it to catch and run. I resorted to an electric drill and an 11/16" socket which bore some rather short-lived results: it would fire up, then when I opened the choke it would overrun then die just as quickly. Went through that process about three times before I sat back to have a think. It has spark, otherwise it would've never started, the timing must be correct otherwise it would have never started, no obstruction in the silencer (I checked), and it's getting fuel - but is it getting a steady supply of fuel? So I pulled off the banjo bolt and discovered sludge in the passageways of the bolt. I then decided to give the tank, petcock and fuel line a thorough clean. And a good thing I did...
I found still more sludge in the petcock valve, but the bowl above was only from the fuel tank, and nowhere else! I figured I'm going to need to clean down the carb, but in the meantime figured I'd put everything back together and give it a run to see if it'll run after all, and if so hopefully catch it 'in the act' of binding on me.
No such luck. I pulled the '35 Atco off the service trolley, placed the '54 Atco on, strapped her down, and I got her fired up on the 2nd or 3rd kick. After a little up & down, I got her settled into a steady RPM and then engaged the clutch. It worked just fine; the drive roller spun as did the cylinder cutter, no problems whatsoever. I let her spin away like that on the stationary trolley for what must've been a good 15 minutes or more, waiting for something to happen, but nothing did. Frustrated, I took the mower off the service trolley, wheeled it into the back garden and put it under load. It didn't move 3 feet before it 'locked up' and shut down completely. Back to the workbench now, and time to see what's happened...
My hands were far too greasy and oily to take the pic of what I noticed with my iPhone, so I've added a pic with illustrations to show what I saw:
The chain had skipped the teeth of the drive roller sprocket (1), placing a lot of tension on the intermediate sprocket set (2), which in turn stressed the drive chain to the cutter. When I corrected this, I noticed a considerable amount of play in all directions around the spindle (2), and the drive roller chain seemed too loose to be correct; when I pulled the key link out and tried to figure out how many links extra there were, however, I couldn't even get to half a link overlap, much less a full one, so I figured it had to be correct, and the slack in the chain probably caused by the slack of the intermediate sprocket to the spindle. On closer examination I noticed the spindle appeared to be bent as well, which could be the root cause of the binding, after all. I've since taken all of the gears off and begun a thorough cleaning. Has anyone ever experienced this issue with this model of mower before? It looks now as though I'll need a replacement spindle and possibly an intermediate sprocket set since the bushing on the original one is probably too worn to be reused. I've purchased these off e-bay.
Disassembly was pretty straightforward, and perhaps simpler than the 1935 Atco. In comparison, it appears the '35 Atco was probably over-engineered a little, but not uncommon I suppose given the period of manufacture. I had the entire mower broken down into its individual parts in less than an hour.
The engine, a Mk I midget I believe, is a happy little runner, however when I took the silencer off to inspect the barrel the port was caked in coke, so I'm going to go ahead and invest some time and money into completely restoring the little midget - I'm going to install a new HT lead, probably replace the points, condensor and coil, give the crankcase and magneto castings a good, thorough cleaning and polish, and the barrel a decoking like I had done on the '35 Atco. This will be its own little project, separate from the mower.