OMC coil on Villiers core

[cajuncook1]

Well, I have good spark and fresh fuel mix and cleaned the carburetor, but does not want to start. :-[. It definitely seems like a fuel deliver issue. I put fuel mix directly in the spark plug hole and all it does is pop. I have been doing this for weeks and it is frustrating.

I then inspect the power head and crankcase for signs of cracks or what not and I notice a bit of oil leaking from the crankcase base where the drive shaft casting tube connects. I notice a loose nut on the back stud so I tighten it. I then notice there was a missing front stud, nut, and spring washer that goes to the drive shaft casing tube that connect to the crank case. I turn over the fly wheel and I feel suction!!! Bingo!!!


So, I place my finger over hole where the missing stud is suppose to be and crank the motor and she starts!!!


Here is a picture of the missing stud, washer and nut.




So now I need to locate part 1288 5/16 inch stud, S1290 spring washer and 1289 nut.

Here is the diagram. (parts 15,16,17)




Here is video of me starting the motor!!! Sorry the video is kind of dark :-[








Cheers,

David

[cajuncook1]

That looks like a good solution.

My only concern would be the screw in HT lead.

I would be much happier soldering the HT lead to the coil outlet.

All we need now is a cheap supply of OMC coils, I bought my last 4 from Texas.

H-A

H-A, I thought the same thing about the security of the high tension lead. I was thinking about soldering it as well, but the OMC coil has a screw on type spike so it holds it pretty good.

But....I would like some added security. This modification is work in progress so I will have to think on it, but don't want to modify the Seagull originality to much.


I have considered using the original metal clip that originally held the high tension spark plug lead to the coil. I might find a way to secure it to the metal clip that is secured on the left and right laminate studs with brass washers.

Here is a picture of what I am talking about.





Cheers, I am excited this modification is so far is working!!!

David

[Collector Inspector]

Thinking out of the square usually gets a spark aye?

B

[phil]

So I tried to fit some older OMC universal coils on a 1959 SJP stator plate, unfortunately the diameter is too large to let the central part of the flywheel pass. I don't have any new ones in stock to try they may have less diameter. Not sure why Cajun's fit and mine don't.

If you want to try this it might be best to measure the coil dia. exculsive of the laminations before you buy it. The ones I tried were 44.5 mm or 1 3/4" in dia. The flywheel cam high point was on the opposite side. It appears that a coil diameter of 40-41.3mm or 1 9/16"- 1 5/8" might work.

[cajuncook1]

Phil, I popped the flywheel off and measured the coil with a set of digital calipers.

Diameter = 1.7175 inches
= 43.62 mm

Height = 1.237 inches
= 31.42 mm


My flywheel's high point of the cam barely misses the OMC coil by a hair. So, I can see if another model's flywheel had a slightly larger cam, it would be an issue. But...................I have another solution to this issue. Not as clean as the first coil fitting, but would take a very minor modification to the ignition plate.


This is the currently OMC coil fitting using the core and wing laminates as I previously displayed.





The second option **** I have not tried this second option, so I do not know if it will work. I would like to try it in couple of days when I am able to get off of work. This was my back plan if the first did not work****

- You can leave the old Villiers coil and core intact.
- Place the OMC coil on its side with ground and points wire facing up.
- Center the coil from the outer rim of the ignition plate and plenty of distance from the high point of the cam on the fly wheel.
- Drill a small hole on the bottom of the ignition plate. Making sure it is of adequate distance to center the coil from the high point of the cam on the fly wheel and outer rim of the ignition plate.
- Get an appropriate size flat brass head screw, thin washer, and nut to secure the coil to the ignition plate. This is to secure the coil to ignition plate. (Secure it from the top but do not use a washer too large to mash the wires. Secure the screw with the brass nut under the bottom of the ignition plate.
- Clip the wire going the points and condenser and connect it to the green wire/primary windings wire on the OMC coil.
- Ground the black/ground OMC coil wire to the closest wing Laminate. Just like it was displayed in my first OMC coil option. See the first picture in this post.
- *** Make sure you attach your spark plug wire/ high tension lead to the OMC coil spike prior to securing it to the ignition plate. Make sure the coil spike opening is facing the original coil outlet on the ignition plate.

**** Please make sure the coil is far enough so the magnets do rub on it and that it is far enough away the flywheels cam will not rub on it before you drill your hole!! ***

**** I have not tried this second option, so I do not know if it will work. I would like to try it in couple of days when I am able to get off of work. This was my back plan if the first did not work****






The OMC core on its side like in the pictures is Height = 1.237 inches = 31.42 mm

The height of the coil on its side displayed in the picture is lower than the wing coil laminates and about the same height of the metal housing containing the points and condenser.




Not all models of the Seagulls are the same dimension, so be very careful and measure before your alter your ignition or purchase a coil. The first option worked for me, but I have SPJ 1964 Forty plus.


********* I will get back with the finds of the second OMC coil option, when I get a chance, unless someone willing to try it first.*******

Please use common sense, I did this as an experiment to get my Seagull going. Fortunately it worked. I would hate for someone to ruin a fine motor, so if in doubt use original OEM Villiers coils.

Cheers,

David

[phil]

The cam height was not the problem the cam profile height was on the opposite side from the coil when I tried to get the flywheel on. It was very close but no go. If it had gone on there would still have been the cam. I don't know how much extra clearance that might take.

If you get a chance it would be interesting to know the measurement you get between the crankshaft and the greatest dia. of the coil on you motor, also the thickness of the flywheel sleeve that rides on the crankshaft with and without cam profile.

On your plan B, how can the coil work unless it has a core that is placed very close to the magnetic field from the flywheel, as it is when you swap it for the Villiers coil? The lamination ends in that case are very close to the interior of the flywheel magnets probably on the order of about .020"

[phil]

Ok, I should have known but the points are normally open and fire on the cam low spot. So that means I only need a little less than 1mm clearance just as you measured. Thanks

[Stelios_Rjk]

Many bad things can happen to a Seagull. In a MK1 magneto like yours I fit with success the M1361 replacement coil. In an MK2 (wipac) which made the engine run intermittently I fit an external condenser, again with success. On the second coil (MK2) I had 4.7Kohms and a faulty condenser.

Imagine how many unsuccessful attempts I may have done

[cajuncook1]

On your plan B, how can the coil work unless it has a core that is placed very close to the magnetic field from the flywheel, as it is when you swap it for the Villiers coil? The lamination ends in that case are very close to the interior of the flywheel magnets probably on the order of about .020"

Well, I guess working all night before I posted plan B was a no no. After, I read more about magnetos and coil systems I realized what Phil was trying to say. But, just for the heck of it I tried plan B and of course it was a no go.


Well, plan A definitely works for my situation and my motor, but it is a little discouraging that it did not work out for Phil.

- I guess, like Phil stated, finding a smaller diameter coil and measuring the diameter of the flywheels cam portion to determine a good fit.
- another thought would be to slightly modify the iron core where the coil would reside. Grinding or filing the back portion of the cylinder core portion to allow the coil to advance a 1mm or 2mm forward to prevent the cam from rubbing. This will only be feasible if by advancing the coil forward 1mm or 2mm will not cause the flywheel magnet to rub on the coil.

[david doyle]

Cool stuff. Just a word of warning though there wont be any rubbing, if the flywheel hits anything the crank will bend like a wet noodle. Just as a heads up some USA seller has a pile of USA made NIB 6V 2 pole bike coils on fleabay right now for $4.95 a pop! A walmart lantern battery and a condenser and you are on the water for about 20 bucks.

[Charles uk]

Have you got one of these going yet David & were there any probs we should look for?

[cajuncook1]

Charles, yes I have had my 1964 Forty plus going, but for only short periods. I am missing a front stud, nut, and spring washer that goes to the drive shaft casing tube that connecst to the crank case. This prevents adequate negative crankcase pressure for fuel delivery. But if I obstruct the opening where the stud, spring washer and nut go, then it starts very easy and runs fine. But I only run it for 20 sec or less, because I don't want it to over heat. Phil, has been generous to sell me a front stud, washer, and nut. He has to send it by postage from Canada. After, I get the stud and install it, I will run it for longer periods and let you know how it does.


This is the original set up and it works for my application, but Phil has had some issues with the flywheel's built in cam rubbing against the coil at the high point. My cam misses the coil by only a 1mm at the high point, so it works. The coil I am using is the Sierra 18-5181. These are the dimension of that coil when measured using my digital calipers.

Diameter = 1.7175 inches
= 43.62 mm

Height = 1.237 inches
= 31.42 mm

The official product dimensions were listed by Phil as 44.5 mm or 1 3/4" in diameter. Don't know why mine is slightly smaller.








That is why I made this previous statement.

- I guess, like Phil stated, finding a smaller diameter coil and measuring the diameter of the flywheels cam portion to determine a good fit.
- another thought would be to slightly modify the iron core where the coil would reside. Grinding or filing the back portion of the cylinder core portion to allow the coil to advance a 1mm or 2mm forward to prevent the cam from rubbing. This will only be feasible if by advancing the coil forward 1mm or 2mm will not cause the flywheel magnet to rub on the coil.

If, I can find a smaller coil that may work, I will try it and post it.


Charles and Phil, I will keep you posted when I get new information!!

David

[cajuncook1]

Sorry, double posted

[phil]

I didn't have a new one to try so I used an older one. It had the same appearance as the Sierra coil so I thought it would have the same dimensions. My guess is that the newer Sierra coils (Prufex) may be somewhat smaller in diameter, it doesn't need much.

[david doyle]

Have you got one of these going yet David & were there any probs we should look for?

I followed CI instructions which appear in another post. Worked on gull and works on an OMC Iron horse engine with the same condenser. Attend any antique engine show on either side of the pond and you can see as many operating as you want. Heck you hang 3 gulls off your transom and fire them all with the same coil Thanks oyster for the villiers mag to play with. I was under the impression that disccusion of non OEM ignition was frowned upon ?