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Collection, Preservation and Display of Old Lawn Mowers

Atco B14 commodore

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Hi. I have just acquired this machine to assist/take over the cutting of grass at my allotment as I seemed to spend more time pushing my old Ajax Mk4 around than growing! Anyway the mower works very well (not bad for £20)  but the rear powered roller is quite aggressive in that it pulls very strongly and too fast and I am not a weakling. This happens at any  setting of the throttle - slow or fast. Now this may be a feature of the machine but I can manage it by 'feathering' the clutch engagement lever but this is not good practice. The manual talks about the traction clutch for the rear roller but gives no further detail. Is this something I have to live with or is there an adjustment? I also have an old Webb 18" standard with a driven rear roller which is much easier to control and turns much slower, increasing speed in conjunction with the throttle.It's too big for the allotment though.  Any help or suggestions would be most welcome. 

wristpin Sat, 27/08/2016

I suspect that it is just the wrong machine for the confined area of allotment paths. The traction clutch is designed to be either in or out and not to vary the forward speed so you are stuck with what the manufacturer decided was the " right" speed for the intended purpose. The engine throttle should give you some variation of useable speed , assuming that the governor is operating correctly and reacting to changes in load. 

I am imagining that your allotment mowing is of a utilitarian nature rather than lawn mowing so it may be worth switching from powered or push cylinder machines to a push rotary on decent sized wheels with lower rolling resistance  and allowing you to choose your own speed. 

Suzanne Shaw Sat, 27/08/2016

Thanks for that Wristpin. I suspected as much but it's nice to hear from an expert and this is the second time you have helped me. I can push the B14 easily so I'll continue with it adhoc as it takes the hard work out compared to a non-powered push mower and I can use the power roller when i want to. I will still continue with my Ajax or Maxees but these are difficult if the surrounding grass is wet or longer than usual. An occupational hazard of our weather. Typically we are now in drought!

 

Congrats on your award.

Suzanne Shaw Sat, 04/02/2017

Further to my previous posts, I found the Atco to only run on full choke and it started to soot up visibly over time. It still ran ok for several months but recently became harder to start. It was not obvious which setting the carb was on initially as there were no indications except what appears to be a C or O on flipping the slide switch so I took off the air filter and it was then obvious. These usually correspond to a Dellorto carb I am reliably informed. Information provided on the fora seems to indicate that I should check out the carburettor as petrol is definitely flowing. In trying to identify it, I was initially unable to determine the make but today I found some indentations on the seam that says MIKUNI corporation. Now I am guessing this carburettor was never intended for this machine so I appear to have a mongrel. I have removed a carb on my old Webb but that was very easy compared to this job. Any tips, ideas please? Many thanks. Suzanne

hillsider Sat, 04/02/2017

From your description of the fault it does sound as though you may have a blockage in one or more of the jets in your carburettor that need to be thoroughly cleaned. 

However it would be helpful if you could post a few photos of your machine including the engine / carburettor set up, this could make it easier to identify the mower and give you better advice.

Suzanne Shaw Sun, 05/02/2017

I will post photos when able as the mower is over my allotment at present and it is extremely wet over there. I need to take photos anyway so I know, hopefully, where everything goes once disassembled. I am grateful as always for help.

 

wristpin Sun, 05/02/2017

Can't place a Mikuni carb on an Atco unless it was the one fitted to the electric start Mitsubishi engine offered as an option the Commodores for a while.  As has been said, images will help.

Edit

It appears that my hunch was right. The Mitsubishi engine with a Mikuni carb was used in 1987. That is unfortunate as that carb was very susceptible to dirty/stale fuel issues and usually only responded to ultrasonic cleaning - if at all.

https://www.dropbox.com/s/lt7q0uhgvy5s2y2/Mitsubishi%20and%20Mikuni%20c…

 

Suzanne Shaw Tue, 07/02/2017

Main

Photos as promised. My camera phone is old so images are not the best.I hope they are sufficient for identification. Thanks Wristpin for your information. I don't know how you know all this stuff but it made for interesting reading, however I am not put off. At least it will give me experience of diagnosing, fixing and maintenance - and if I cannot fix it; it's not a great loss.

wristpin Wed, 08/02/2017

That is the Mitsubishi engine and back in the day their carburettor problems were a pain . The copy of the service bulletin that I posted acknowledges the problem and offers a couple of solutions which from our practical experience were seldom totally and permanently successful. From the prospective of a business not wanting dissatisfied customers the best permanent solution was for the manufacturer to fit a different brand of engine.

 

Suzanne Shaw Wed, 08/02/2017

Thanks for the information. I'll have a bash at it anyway as it is only a backup when the grass is too long really for my push mower. Nice to know the background and if someone expert like yourself says it's a pain - well I have very low expectations of me getting it going properly. It will be a while before I can remove and work on the carb as I don't have a workshop and have to work in the back garden.

Suzanne Shaw Sat, 18/03/2017

Well, after a few weeks I had the weather to work on this machine. The spark plug was sooted up and the carb gasket was blowing slightly from the soot marks seen. The carb bowl had a little sediment but he main jet was blocked at the tapered end. I didn't see any gumming up and asked a neighbour who is a petrol head for his advice. Some judicious use of carb cleaner and the finest copper wire to test the hole was clear and a general clean all over was employed. The float and everything else looked ok. New petrol tap fitted as the old one was a push/pull affair that leaked like a sieve. Everything put back on the machine with new gasket (home made), new spark plug and a smear of gasket sealant at either end and ..............it started first time. I waited for it to warm up and ran it on normal for over 5 minutes with no problems. In use, it occasionally changed to hunting a little and after an hour of fiddling with the mixture screw and adjustment of the choke control, I finally got it running well. It is very sensitive to throttle and choke settings and just when you think it is perfect; the next time you start it up within a few minutes, it starts hunting again. I have reset it up and await the next use to see if it holds. Despite the temperamental nature it does not stall and is cutting very well at my allotment and I shall persevere with it. It's nothing like the old Briggs and Stratton on my Webb though. That workhorse runs like a dream with no fussing. I have certainly learned a lot from the various contributors and fora on this site and now feel quite confident in some aspects. My thanks to all.

wristpin Sat, 18/03/2017

Seems that you have more or less got the machine beaten. Perhaps, in the due course of time , the carb will benefit from an ultrasonic clean.

wristpin Sat, 18/03/2017

Seems that you have more or less got the machine beaten. Perhaps, in the due course of time , the carb will benefit from an ultrasonic clean.