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E10 is as far as I know allowed for these engines, but I’ll switch to E5. Given the age of these engines, I was surprised and pleased that unleaded is OK! 🙂
I took a picture of the electronic ignition module that’s fitted. It’s similar, as said before, to the chevroned article pictured above. I guess they all work the same way. I have ordered a replacement just in case for the princely sum of £12 (as I also have another ‘350″ which has points ignition). Could not find a “Meco”.
The coil is as described above. Two LT connections, one earthed, one HT lead. The non-earthed LT wire goes through the pictured ignition module to earth. No kill switch. I will have to fit one, ‘cos it’s hard to stop the thing (when actually running) apart from by shorting the HT lead to earth.
The odd thing is that it worked perfectly, twice, for maybe 15 minutes at a time. After, it stopped and wouldn’t start again. I will check to see if there’s a spark now it’s had a rest for a while.
I took the coil off the day the day before running it, to check. It all looked OK, but perhaps I missed a crack in the insulation… but the odd think is it runs fine for a while, then stops and won’t restart apparently due to “no spark”. Perhaps the coil fails when hot?
How on earth does the electronic ignition work? Replacing the points seems to be a matter of cutting off the points connection, putting the LT feed through the electronic module, and earthing the other side! What about timing?? Gah!
I thought I might file off the threads, when needed, and re-cut with as big a diameter thread as possible, because the end of the crank would not be lost, and I could drill and tap internally at some other stage if need be. I don’t know how on earth people manage to butcher things like these threads. Grr!
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Hi, Charlie, thanks for your reply.
I’m rather reluctant to take the thing apart again unless vital, the threads are bad bad bad, as I’d like the machine to do one job in the next couple of weeks before dealing with it.
Anyway.
There are no connections *at all* to the points, only a wire cut off at the exit through the grommet of the cover.
There is a thing that looks a bit like the attached (from “my old machine”) bolted to the aluminium casting that fits behing the cast iron flywheel-blower-fan. Yes, I think it has got electronic ignition. This device has a vertical pattern on it, unlike the chevrons of the attached picture, but is otherwise similar.
The black plastic encapsulated coil under the flywheel is mounted on a laminated “C” shaped metal core. There is a steel screw through the core (that does not screw into anything else) that seems to allow for dismantling the core itself. The core is bolted to the engine with two bolts. There is a magnetic rotor on the crankshaft to generate current when the engine turns.
The HT wire just pushes into the coil, a short length of copper inner being bent back up the outside of the wire to contact the inside of the hole it pushes into in the core. The HT wire goes out through a hole above the coil, and up the back of the engine to the sparking-plug.
One LT connection from the coil is earthed. The other LT connection from the coil is soldered (replacing the wire nut join) to a wire that follows alongside the HT lead out through the hole above the coil; this LT goes to one connection leg of the “thing” in the attached photo. The “thing’s” other connection goes to earth.
I’m at a loss to know how it works, but when it’s actually running, it’s fine. Then it just stops, seemingly with no spark, or possibly – hard to see – an intermittent weak spark.
There are no other cables or connections involved. No capacitor. Nothing.
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Thanks. I have had a go with this. Afrer draining the sludge in the engine and gearbox, I refilled with straight SAE30 (from Toolstation) and SAE90 (Eurocarparts), and after pulling it over for a while (plug out) started it. Good! E10 petrol, as recommended and further looking says is OK.
So, I ran it up and down a piece of ground. A bit smoky. After 50 yards it stopped. Would not restart. No spark.
Investigated, looked online to find where points are (boxy cover, under exhaust, on back of engine). Mystified. No connection to anything! Wire cut off, seemingly a long time ago. Removed flywheel[1], possibility of bad connetion (wire nut) on LT side, soldered, looked further, cannot fathom how this works at all, let alone sometimes. There is a wire running from the LT to earth, another to a small electrical thing with “KB03” written on it bolted to the back (outside) of the cover plate that the coil is attached to which has 2 wires, one from the LT side of the coil, the other to earth. I have no idea what this does. Anyway, I bought it a new sparking plug (NGK B6S, Motor Parts Direct), put it all together again (using a piece of plastic to hold the coil core off the magneto flywheel while the bolts were done up, not sure if this is correct procedure), gapped the plug to 25 thou, and off it went.
Again – did about 50 yards, maybe more this time, a bit smoky, cut out, seeming no spark!
What could it be ? What’s going on with the “no points” ignition system? How the blazes does that work?
[1] Oh woe, woe and thrice woe! Someone has forced a nut onto the end of the crankshaft that does not fit. The threads are ruined, all sharp, distorted, flaky. I did it up again very carefully and not as tight as I would have liked. What can be done with this? I had a desperate thought of filing off the threads, using the root of the thread as a guide, and cutting (say) an M12 thread (coarse or fine?) on the end of the crank. Any other ideas?
