I was recently given an old 2 stroke Pope engine by a relative who had converted it to horizontal shaft with a Villiers cowl crudely fitted. Originally came off a mower. Not sure of model but it is the one which had the flat, oval fuel tank sitting behind which was fitted into three slots which were bent over a bit to hold it in place. They were a neat looking mower, rounded like a VW bug and looked a bit "space age" for the times. The base has long since gone to mower heaven, leaving only the engine. He'd been using it to belt drive an air compressor before retiring it to the back of his shed. It had been standing out for years in the weather. When I asked him about it he said it was just junk and he was going to throw it to the dump. He said it should still go as it was running perfectly before being replaced by a modern Honda engine. He could see I was interested in it and asked me if I wanted it. I wasn't going to say no and came home smiling from ear to ear.
Very rusty so I sprayed all the nuts and bolts with fish oil and left them a day or two. Pulled it down and find it has a Wico ignition system. Looks very similar to a Victa ignition system from the time. The coil tested good for its age. I have removed the points and condenser in hopes of installing a modern electronic ignition module. However the flywheel magnets are very weak and I've been told that if the magnets are weak on a Wiko I won't get the EI to work. As luck would have it there are hollow spaces behind the magnets which I have packed with rare earth magnets. So the magnets on the flywheel are now strong enough to hold a large screwdriver in place. The poor old air intake manifold had been jammed into another pipe to extend it for horizontal use, but I managed to cut it free only to find it has been threaded. I will fill the threads with JB weld and smooth it off so it can slot into the carby the way it should. I wish to return it to its original vertical format. I doubt there will be any Pope bases out there that might fit it as these are very rare, so in the meantime I will adapt it to fit an old H.G. Palmer base.
I have not been able to find anything about converting early Pope engines to EI on the internet. The setup looks so similar to a Victa that I am sure it must work, providing the magneto is up to it. I recently successfully installed an EI module on a 1970 Victa Mayfair, but of course Wiko and Pope were different so I am a bit concerned about the timing. I also wonder if replacing the Wico coil with a Victa coil could be the solution in the event that an EI fails to work. In my experience, so long as you have no more than 2 magnets, those EI modules are usually "intelligent" enough to detect the correct timing.
My question is, has anyone else ever tried an electronic ignition module on a Pope with Wico coil, or on anything with a Wico coil for that matter? Am I wasting my time even considering this, or is this a worthwhile exercise?
I can't understand why it will not work. The only thing that comes to mind is the Wico coil is perhaps too weak for the EI to detect it? But then again I have had some very weak Briggs coils and the EI have worked perfectly on those.
One thing I have noticed is that not all EI modules are the same. Some work on some types of engines, others won't. I have had most success with 2 and 4 strokes with the slightly more expensive STENS one. This one is suggested for use with Kawasaki engines. I have bought some of the lower priced EI and found they will not work on some engines. Why, I do not know.
I could never get an EI to work on Kirby Lausen engines, but then I read where other people have had great success on those engines with EI. So I am a bit baffled.
One suggestion made in email to me just now is this: Replace old coil with a new or used one that tests much stronger and fits the bolt holes. EI modules sometimes fail to detect the very low Ohms on those old coils. You can use a coil from a different engine, so long as it fits and is of similar distance from the flywheel magnets. A modern one will be stronger and so the module will detect it. Also, when many people wire these modules in they make the mistake of not earthing the coil wire. Instead they splice the twin wires together and run this to the module. This will not work as you are killing the ignition. The coil bare wire must be earthed near to the coil. The other covered wire goes to the positive terminal on the module and you can splice in a kill switch from that wire. I have seen dozens of cases where people have spliced the earth wire with the positive wire and wondered why their module would not work. Good luck!
Last edited by vint_mow; 21/04/2206:43 AM. Reason: More information
I remember AVB pointing out some time ago that some early magnetos were negative earth and some positive earth. I have no idea which is which or how you can test them. All I can say is try it with a standard module and if it doesn't work it may be the module is wrong. Probably a dumb idea if it didn't work then connect the module in reverse. Probably shouldn't work but worth a shot
The Atom modules were 9 different modules for different engines , Only Atom modules automatically adjust the ignition timing to the same firing position as original points which other ignition modules can not do.
That's what I remember reading about modules.
I know they can be made easily for about $2 to $4 each.
The stens module recommends reversing the polarity for different coils in the instructions.
Yes that is the conclusion I came to after puzzling over different coils yesterday. Without going to the lengths of uncovering the coils to see the wiring I came to the conclusion that those old Pope engines must be positive earth, not negative earth. The wires seem to be coming from the coil the opposite way around to Briggs and Victa. Also I notice that the points snap together on the lower part of the eccentric shaft momentarily, whereas with other motors the points open momentarily on a short wider portion before snapping together. So the whole ignition system seems to be the reverse of what I see on a Victa or Briggs. I am not a technical expert on such things, but to my mind this seems to be pointing to a positive earth ignition system, unless I am mistaken. I've had no problems running the STENS module on different engines, and as you show in your illustrations, most modules are made so you can reverse the polarity simply by connecting the terminals the opposite way around. There is absolutely no reason why an EI will not work on the Pope motor, as there is nothing exotic about it. Just two magnets and points condensor. Providing the coil is good, an EI should work. And of course so long as the timing is right (I have not touched the engine so that should be same as always), it should be simply a matter of working out the correct polarity as Max suggests.
I've never used an Atom module. My understanding is that the newer ones available on the mass market today, e.g. STENS, have largely superseded the Atom EI and are able to sense the correct timing. So long as you get the positive and negative the right way around, there is no reason why they will not fire properly.
Just as a side issue, there is a funny thing about the STENS module and the illustration they provide. The actual module has the negative and positive the opposite way around to what they show in their illustration. They must have wanted to confuse people.
Took my coil to a local auto-electric technician and asked him about the polarity. He said it shouldn't matter and he thought the ignition system looked like a typical negative earth. In any case he said if the EI does not work on negative then try positive. I am getting a few different brands of EI's soon and will test them out to see if I can get at least one to work. Wish me luck.
In the dim reaches of my mind I can remember a little physics. I think that there may be an issue with the way the current is generated through the rotation of magnets and orientation of the wiring. If the ei module is placed inside the magnetic field in some of the older “spinning magnet” type arrangements and it’s orientation is aligned with the magnetic field then I suspect you may not get a working system because one will effectively suppress the other unless the shielding is very very good.
If the different coils have a different number of windings and a different gauge of wire used then I can't see the same module working as well on all coils.
It was found that for each gauge of primary wire thickness, a particular number of turns produced a mini mum number of revolutions required to produce the specified secondary voltage. Increasing or decreasing the number of primary turns away from this specified number of turns in both cases increased the R.P.M. required to produce the specified secondary voltage. For example, for a primary winding wire of thickness 0.040 inches both 120 and 140 primary turns produced a secondary voltage of 10 kV at 400 R.P.M. However, the specified reference voltage of 10 kV was produced at 350 R.P.M. for 130 primary turns. Similarly for pri mary winding wire having a thickness of0.025 inches, a primary winding having 130 turns required 450R.P.M. to produce the desired 10 kV, a primary winding having 150 turns required 350R.P.M. to produce the secondary reference voltage of 10 kV, but a primary winding hav ing 140 turns only required 310 R.P.M. to produce the same secondary reference voltage of 10 kV.
The number of turns in the primary winding of the coils below. Victa 195 Wico 190 McCulloch (Phelon) 200
hey vint_mow, why not clean up points, and put it back together with the condenser... try for spark. if no spark try a Victa condenser, that's what I did , although it was soldering a few wires and using shrink wrap, but it ended up sort of neat. Anyway it worked got spark. Then I checked timing and it was out. It shows in the 1960 manual how to adjust timing......Eventually got it going MAD..... cheers speedy
........................Keep your blades sharp......................
Thanks to all for comments. I am a bit puzzled Speedy as to why I need to check the timing? Surely if I put it back the way it was before, with points set and plug gap set the same, the timing should also be the same. There is only one way that the flywheel can go on. I will try an EI first. If no luck then put back the points and condenser. I think Ironbark might have hit the nail on the head, as I recall my first attempts to upgrade an older Briggs, I positioned the EI module on the plate where the old points were. It would not work, probably because it was within the magnetic field. Later I re positioned it on the outside of the cowl, a long way from the coil, and it worked. I still can't understand why a module will not work. In theory it should. I have tried the same modules on a lot of very different engines, both 2 and 4 stroke and they work. As I said I did have problems with a Kirby Lausen, but as those engines can be prone to multiple problems, it is difficult to say exactly what the problem was in that case. I still dislike Kirby engines with a passion and refuse to touch them.
According to a technician I consulted:- The ignition modules work on 2 stroke whipper snipper engines and on 16 HP gasoline Briggs and Stratton. The wiring in the coils between these extremes is very different, but the modules still work. They detect the timing by algorithm in the chip, so they can accurately detect the build up and decay of voltage/resistance from the spinning flywheel and this allows them to fire correctly.
Ohms on my Pope coil = 4.3 Ohms on new ignition module = 4.54
I have no idea how low or high the Ohms should be on a brand new Pope coil. Perhaps they were around 4.5 to begin with? But this hardly matters when we consider a working ignition coil on a Briggs and Stratton will give a reading of between 2.5 – 5 k ohms.
The technician cannot see any reason why an EI will not work on a Pope engine. In theory it should.
I am still waiting for my EI modules to arrive in the post. In the meantime I tested the coil at 4.3 and the condenser is behaving the way it should (charging up and releasing the voltage and not shorting out). My biggest problem is the points are looking a bit worst for wear and not snapping together properly. It seems worn and the spring seems too weak. I had a look online for points for these old Wico/Wipac and they are non-existent. So it looks like my only hope of getting this engine to go is with an EI module.
Worked on the points yesterday and with a bit of slight bending here and there have got them opening and snapping shut like they should. I have hopes that this motor will give a reasonable spark. Have to work out some way to mount the thing so I can turn it over. I'm not sure how my relative had been using it with the points so bad, but it had been sitting out the back of his shed for a good number of years. The points were not even in line and not closing up fully. The condenser was still shiny and looked new and made me wonder if he had replaced the old one not that long ago. It looks like a stock standard Victa condenser to me.
You could mount it on a 44 gal drum. You would need a disk on it for a bit of load...... Neighbours will be worried if they look over the fence...... speedy
........................Keep your blades sharp......................
