Collection, Preservation and Display of Old Lawn Mowers
Having fun with this ole' 43 but it's defying all attempts to make it spark.
New plug, points sorted but nothing so it looks like I made need to source some parts.
is the magneto assembly available from anywhere?
The image that should've been above
Points sorted - meaning what ? Have you cleaned the faces of the contact breaker points? Do that and adjust the gap making sure that you don’t introduce more dirt while doing so and see where it gets you.
Yep, had several goes at it. Clean, set, clean set. Suspect there may have been some previous fiddling. Plug cable is about as short as it could be, a bit loose at magneto end too. Not sure it would originally have been a suppressor type cap either. One fin missing from flywheel. Contact breaker arm looking worn but still able to adjust points accordingly. Using a big croc clip to hold the plug against the head, or using an inline plug tester both demonstrates only an occasional random spark, if any.
Bought it a while ago, pretty cheap 'cos it was advertised as "was running fine but then wouldn't run. May be easy fix"
The HT lead should be a good tight fit onto its spike but might move a bit in its socket. The coil on your machine is one with the encapsulated condenser and other than a dedicated coil tester proving otherwise I would suspect that it is the cause of your problem.
I'm coming around to that conclusion too.
Wonder where (if ) I can get the bits. Nothing showing on fleabay. GMC, maybe?
Try Jon Cruse at the Hailsham Mower Centre.
So we've probably figured out what doesn't work. I'm just looking around and deciding if I'm just going to replace the coil/condenser or, well, the whole assembly.
The thing is, as it stands, there's no obvious way to stop this engine once it's started. No stop/start, (too old anyway) no shorting contacts on top of the carb, no shorting strap either, although that wouldn't work on a plastic suppressor cap (as fitted) anyway. And the HT lead is too short and too tight just to flick off. I guess they must've set the idle really slow and just let it run to a stop.
Or turned off the fuel and went for a coffee..
You can’t replace just the condenser as it’s encapsulated into the coil. That said, I’ve often wondered whether if the condenser has failed open circuit , one could just piggyback a condenser - even outside the mag. If the condenser has failed short circuit it is definitely new coil time. The coil condenser unit is Wipac S4913 / 4390, an alternative supplier is Villiers Parts
Early SIF engines did not have any external ignition grounding provision other than the metal strip to the spark plug terminal.
Yeah, I knew that, honest. Hence the "coil/condenser".
Resistance on the primary side is pretty low so guessing adding an external condenser ain't on.
Shame really, I did exactly that on a small generator, same value but bigger, beefier. It poked out of the side of the casing like a nose. Worked though.
I may revert to the exposed brass plug connector and a strap. Although I do like my coffee .......
Reading another post, it appears to be THE day for ordering coils/condensers. And a new plug connector. I'll manufacture a shorting strap.
Update: IT LIVES!!
New (new old stock) points arrived today & fitted. Contacts needed a good clean but after that it ran.
Plug is a tad sooty at the moment but there's still plenty to sort out anyway before this sees a blade of grass.