Tecumseh Magnet Spacing

[landlockedmarine]

I am a 2 stroke outboard mechanic. I was wondering if one of you guys knows the practical spacing between the two magnets on an internal mag, 8hp Tecumseh Snow King motor. The magnets were previously glued by the old timer (driveway snow blower fixer) that I bought it from. Of course I got it home and it has no spark. The points, coil and condenser are new. I tried McGyvering an OMC coil earlier and I still have no spark.
I'm going to rig up a magneto charger, but I believe this thing has enough to make a spark. I have 70 2 stroke motors and have made more spark with weaker systems.
I know how far the magnets should be from the coil, but not where the actual magnets should be located and how far apart.
Thanks in advance.

[Nick Stanley]

I really doubt that the air gap is the problem, unless it is WAY off. Usually, as long as there is some clearance it is almost always fine. The proper spec is .015", but we always used a microfilm card doubled up. This worked great. If you still have a problem, I would just replace the coil. If you give me the model and type #'s I will look it up if it is not newer than my manuals.
-Nick

[Andrew Mackey]

If this is a modern 4 cycle engine with the aluminum key, make sure you have the proper key in the engine! If it is the one with the wide face, there are 2 or 3 versions of this key - the thin section is placed offset left, right or centered! if you have the wrong key, the magnets will not be in the proper position in relation to the coil when the points open. Also, make sure the points timing cam is installed right side up - I have seen them reversed also.
Andrew

[landlockedmarine]

I was asking about the space between the two magnets, not the space between the magnets and the coil! Where are the magnets supposed to sit on the flywheel? I have all new components (coil, condensor and points), except the flywheel. I think the old guy glued the magnets too far apart and in the wrong location. Can you help here? I thought they are supposed to be located at 4 o'clock if the keyway is at noon.

[landlockedmarine]

A few days ago I posted a thread. The replies did not address the question, so I will rephrase. I was asking about the space between the two magnets, not the space between the magnets and the coil! Where are the magnets supposed to sit on the flywheel? I have all new components (coil, condensor and points), except the flywheel. I think the old guy glued the magnets too far apart and in the wrong location. Can you help here? I thought they are supposed to be located at 4 o'clock if the keyway is at noon.

[Tom Werner]

For whatever it's worth, I repaired a 5 HP Snow King a few yrs. back which had no spark.either. When the flywheel was removed the problem was obvious. One of the mgnets moved out of position. I was the first to work on this engine and had a hard time believing THE FACTORY USES EPOXY to mount them, The position where it belonged was obvious, so I put it back the same way. Problem solved. The spacing between them I imagine should match the poles of the coil core. Hope this helps Tom Werner in WI

[Junkologist]

This is kind of speculation on my part, but I think the magnets need to placed in such a way that magnetic flux is created in the coil core and broken just before the points open up. In other words, the magnets need to just be passing the coil core as the points open up.

What I would do is look at another engine with a flywheel magneto and examine the placement of the magnets and their relation to the coil core when the points open up. If you set yours up in a similiar fashion, I would think it would work. Hope this helps.

Happy holidays!

Mike

[landlockedmarine]

Well... Thanks for your advice. I tried everything to get this to spark with no luck. I removed the magnets and refixed them and still nothing. In the meantime, I remembered a local guy that sells all kinds of small engine gear on the side. I contacted him and got another flywheel. This time it worked 100%. It turns out the flywheel I received with the motor was the correct casting, but the magnets that were installed were too small, resulting in a weak, limpwristed spike on my voltmeter (only).
I found a flywheel with the internal generator (full of large magnets). I figured that there would be enough magnetism to power anything. It works perfectly.
Thanks to Andrew, Junkologist, Nick and Tom for your replies. BTW I bought the Lindsay Publications book "How to Build a Magneto Charger" by David Gingery. The next time I get stuck like this, I'll nail the problem right away.