ATCO Standard 16"help required

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machine shop at...
Last seen: 1 month 1 week ago
Joined: 31/08/2020 - 16:51
ATCO Standard 16"help required

Hi All,

I am new here so I thought i would introduce myself and my new project.


By day I am an engineering manager in a company that makes gas turbines, by night I tinker in my shed with mechanical projects.  Some of my previous projects include building a blacksmiths power hammer, restoring a series 3 landy and restoring old tools.  If you want to find out more you can find me on youtube under 'Machine Shop at The Bottom of the Garden'.


I have picked up an ATCO standard 16" to do up.  It has been sitting in a shed for 50 odd years and so i have assumed is a non runner.  I don't have a lot of experience with mowers or littel 2 stroke engines, but I am fairly experienced in taking things apart and not having too may spare bits when i put them back together!


I have a couple of questions (I am sure there will be more!!).  The first is I wanted to take the crank out of its case to thoroughly clean it, but I was struggling to remove the sprocket from the crakshaft.  I tried a puller and warmed it, but before I put it in the press and apply serious force I wanted to ensure that it can come off.  I also wanted to know whether there was a shoulder on the sprocked component and whether this constrained the crankshaft axially.  I think I may have moved it slightly and so may have to press it back on to maintain correct clearance to the crankcase bush.


The second question is whether the starting handle interface is screwed onto the clutch shaft.  I have lookeds at the parts list and it looks through it is (it also has flats on it) but before I employ a long bar on it I wanted to check.


Thanks all.Look forward to making use of your experience!


wristpin's picture
Last seen: 1 hour 52 min ago
Joined: 23/05/2012 - 22:09
No experience of that engine

No experience of that engine but on later Villiers two strokes the cranks are threaded. Conventional RH thread. Strange thing is that the Atco Standard parts list on this site appears not to show the crankshaft. - does show the sprocket though.

Messorestore's picture
Last seen: 16 hours 57 min ago
Joined: 19/07/2020 - 21:52
Hi, my 16" Standard Atco

Hi, my 16" Standard Atco certainly had the starting handle receptor plate on a screw thread. However I don't know if this would be year dependant as to whether the design was slightly different as upgrades were quite common. I would certainly be wary before exerting too much force. Sorry I can't help with the crank as never took mine out. Hope this is a little help.

Last seen: 4 weeks 15 hours ago
Joined: 16/06/2010 - 23:06
Just to give you a bit of

Just to give you a bit of hope:

Unfortunately I haven't needed to touch either of the areas you are asking about. Sorry! However there is a thread about getting it to start that may come in handy when you get to the sparks department.

olcadmin's picture
Last seen: 1 hour 43 min ago
Joined: 07/08/2009 - 18:22
The parts list on our site

The parts list on our site clearly marks the Starter Socket (part 5427) as "improved screwed on type". This implies that earlier versions of the Standard did not have a "screwed" socket - certainly my 1921 "Oval Frame" does not.

Further, although it's not dated, the parts list only covers the 16", 22" and 30" models which were the first three conventional models after "Oval Frame". That presumably means our copy is from somewhere between 1922 and 1925. On the "Oval Frame" it's pretty clear that the socket is not screwed on - it wobbles and has a pin through it to hold it on the shaft - but I don't recall seeing one on any other Standard (happy to be corrected if I am wrong).

As messorrestore says, models did change but with the Standard, not that much. They got the design more or less settled very early on which was one of the reasons it was such a popular machine (it helped keep costs down and servicing simpler among other benefits).


OLC Admin

machine shop at...
Last seen: 1 month 1 week ago
Joined: 31/08/2020 - 16:51
Thanks all.  The starter

Thanks all.  The starter interface unscrewed fairly easily with a few sharp blows and a flogging spanner.

I think I will leave the sprocket on the crankshaft as I only wanted to remove it to clean the crankcase more easily.

The next job is disassembling the clutch shaft.  The thrust collars (according to the parts list) are held in with taper pins.  These do not seem very keen on being removed.  Has anybody taken this assembly apart before?  My aim is to take the clutch actuation mechanism apart to give it a good clean and lube.