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Collection, Preservation and Display of Old Lawn Mowers

Atco Commodore B14 Non-starting.

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Hello everyone, thanks for adding me. I have been repairing mowers for several years now especially Atco / Qualcast and Briggs, so happy to help others when I can.

Unfortunately in this case I need help myself! I currently have a Commodore B14 which I was told had problems starting. I've thoroughly cleaned the carb, 3-pole ignition AND points and it has a good spark with petrol coming through to the spark plug (spark tested old-fashioned way using my thumb!) After using a replacement carb, many plugs, changing the points etc, it still will not fire. I've read on your forum that it could still be the sealed ignition unit ie; maybe giving a weak spark - not enough to ignite the petrol, so guess I should really invest in a volt meter to make sure? By the way, I replaced the 3-pole with another identical (Wipac) and this also sparked, however, this did not have the fitting on the plate to take a set of points.

Thanks for your know-how!

Kevin

PS I have posted a pic of the Zenith (Type 13 - TCA 2) carb type plus the ignition set-up.

 

Forums

wristpin Tue, 06/06/2017

The first problem is that to the best of my knowledge the Commodore never had that engine. It should have the A114 with breakerless electronic ignition - usually painted gold , I think. Also, the A114 had a Dellorto carburettor and not the Zenith in your image. 

So, it may be that yours has been fitted with either a Suffolk cast iron 75 or 98 cc engine which would have had a points ignition system or  Suffolk A98 aluminium block engine, the early versions of which had points and an air vane governor before switching to a mechanical governor and electronic ignition.

Once we have worked out what you have we can start to tackle the ignition issue. The worst case scenario is that the ignition components have been mixed but not matched!  The flywheels are not interchangeable between electronic and points systems and to further confuse matters there were two electronic systems , capacitive and inductive each with their own specific flywheel.

hortimech Wed, 07/06/2017

Are you sure it is a Commodore ?

Everything Wristpin says is valid, except, from the picture of the carb, I think you can discount the A98, the carb on this was integrated with the inlet manifold, if I remember correctly.

Can you post pictures of the engine and machine.

 

kayjay777 Wed, 07/06/2017

Hi everyone, thanks for the great replies. Sorry, this is my fault - I forgot - the chap who I bought it from, had a replacement engine put on it. It's definitely a Commodore as it was apparently bought new by his father. surprise

hortimech Thu, 08/06/2017

Okay, it looks like a 75cc Cast iron Suffolk, I say looks like, because the second picture is chopped off just where it would prove it one way or the other ;-)

If you look at the two nuts, near the sparkplug, that retain the main cover, if there is a headbolt between them, then it is 98cc, if there isn't, it is a 75cc. Or to put it another way, 8 headbolts = 98cc, 6 = 75cc

It should have contact breakers, so you will need to use the ignition plate shown in your picture, you will probably need to clean the points and then reset to 18thou

You should then get a good spark when you spin the flywheel by hand, but watch out for the governor airvane, it is very easy to catch your thumb on it.

 

kayjay777 Thu, 08/06/2017

@Hortimech, thanks for that. Yes, already cleaned the breakers and re-assembled and getting a spark. Still no sign of firing I'm afraid.

wristpin Thu, 08/06/2017

8103 on the block makes it a Model 75G 14 75cc lump. and as Hortimech says, with points ignition. Very true what he says about minding your thumb when spinning the flywheel  - nice clean cut that takes ages to heal! That's why I habitually nip the corner off the vane then round it off.

The stator that you showed has no condenser which means that the coil should be the later pattern  with an embedded condenser which may have been a production improvement from the assembly point of view but has the disadvantage that in the event of the condenser failing the coil is written off.

If the flywheel has a number on it there's a possibility that it will be E9300

kayjay777 Fri, 09/06/2017

@Wristpin - thankyou for that. I'm going to take it apart again later so will check the flywheel yes

kayjay777 Sat, 10/06/2017

Quick update - can now confirm it's 75cc. had a new set of points come today so put them in at the recommended gap, but still a weak, intermittent spark. Am now guessing the sealed ignition is on it's way out?