Eiseman magneto problems on RD7

If it has sat for 2 years it could be the impulse coupling is not happening. Usually mags that don't work just need the points cleaned up, and you've done that already.
The magneto rotor needs to turn fairly fast to generate enough juice to fire the coil. It will not turn fast enough just by cranking the engine by hand. When you crank the engine by hand the impulse coupling will stop the rotor and wind up a drive spring in the coupling. At a certain point the coupling will release the spring, the rotor will spin over and the mag will fire. Your magneto may still fire if you can crank the engine over much faster. By sitting for 2 years the pawls in your impulse coupling may not be catching because they have rusted or gummed up. I would take it apart to see what the problem is.
I am by no means an expert on Magneto's, but I have learned enough by tinkering with them to dig myself out of trouble (most of the time). Good Luck!

[quote="zootownjeepguy"]If it has sat for 2 years it could be the impulse coupling is not happening. Usually mags that don't work just need the points cleaned up, and you've done that already.
The magneto rotor needs to turn fairly fast to generate enough juice to fire the coil. It will not turn fast enough just by cranking the engine by hand. When you crank the engine by hand the impulse coupling will stop the rotor and wind up a drive spring in the coupling. At a certain point the coupling will release the spring, the rotor will spin over and the mag will fire. Your magneto may still fire if you can crank the engine over much faster. By sitting for 2 years the pawls in your impulse coupling may not be catching because they have rusted or gummed up. I would take it apart to see what the problem is.
I am by no means an expert on Magneto's, but I have learned enough by tinkering with them to dig myself out of trouble (most of the time). Good Luck![/quote]

Can this be done with the magneto mounted on the engine, or does it need to be taken off and disassembled and cleaned up? I think that's what the problem is because the magneto doesn't click or snap when I crank it over. The magneto on my other RD7 clicks nice when I crank it.

Unfortunately, you will have to remove the mag to take it apart. Be sure to mark the impulse coupling and magneto drive in the engine so you can put it back in and get it timed right. Good Luck!!

When I have a stuck/sticky impulse I just drench it with oil. Look at it to see where you might direct oil to get it inside the impulse and squirt oil in that direction. This usually works for me. If you use a penetrant (WD-40, etc.) follow it up with oil.

Daron

RD7,

If the magneto is not producing a spark...it is not the impulse coupling. That only delays the timing for easier starting. If the impulse coupling is stuck...the magneto will still produce a spark.

Make sure the P-lead is not gounded anywhere. If points are OK...how is the magnet itself? Mine got so weak on my TEN that I had to heve it re-energized.

Pat

I disagree with Pat, in my experience you must have impulse or you have no spark.

It's actually some of each...the impulse coupling delays the timing and engages the wind up spring until it is released by the cam and gives the armature enough rpm to make adequate spark for starting. If you don't hear the function click of the impulse coupling that is where to look.

With the armature turning over at non impulse rpm the spark is to weak to do anything until you get to about 200+ rpm which is about where the impulse coupling is disconnected by centrifugal force.

Thanks for the information. One of these days I will clean up the impulse mechanism and lubricate it and see what happens. It doesn't click at all when I crank it. Like I said before, the magneto worked fine before around 2 yrs ago.

An Eisemann will create spark at the points even when turned by hand backward (off the machine). I would see if there is spark at the points. You may have to discharge the condenser by simply grounding out the spark plug wire first.

Have somebody crank it over and see if it sparks at the points. No spark, maybe bad ground on the coil. Check connections and clean them. The condenser itself maybe bad. If there is a blue spark at the points, then the cap may have problems. The terminal connections for the spark plug wires get corroded inside the cap. I take a piece of steel wool, cram it in the connection hole and turn it with a screwdriver. This will clean it right up.

You probably have some impulse problems as well, but Eisemann are pretty well built compared to the later cat mags.

Something else to keep in mind HEI wires don't work good on point and condenser systems. Many a times I have found wrong wires on machines that turn over and won't fire.