----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----Over the last couple of weeks I have been asking around how to approach my mag problems.
The symptoms are as follows:
Log books show the mags were not overhauled since 1992.
hard to start a hot engine.
The gasket on the cover of the left mag has disintegrated and the mag needs drying out if not started regularly.
relatively hard to start cold. When I pull the starter I can hear the impulse coupling click on the first half turn of the prop, after that, the prop tuerns but I hear no clicks. When it does start it will start on the first half turn and never on the following turns, so starting the engine is a series of short pulls. The current mags are Eisemann LA-4's and have about 900 hours TT on them.
Only the left mag has an impulse coupling on it and some people believe that to be a cost saving tactic
The advice of my local mechanic is to rip them both off and trade them in for a new pair of Slicks with two impulse couplings which would double my chances of starting and reduce the chances of not being able to start the engine if the only impulse coupling I have should fail. ( About $1,600.00 )
On talking to a mag rebuilder, he had the following advice:
Take both Eisemann's out, take them apart, clean them well and replace the seals, brush, points, bearings, everything else that may need replacing that can be bought from El Reno Air and rebuild them. He claims "There was nothing wrong with Eisemann magnetos and they are as good as Bendix and a little better than Slicks." (WOW!)
If the coil is strong, keep on flying them, if they last another 56 years by then I may be able to replace them with an FAA certified electronic ignition. (One would think).
If the coil is not strong, El Reno still has some but they may not last another 56 years.
As for the single impulse coupling, one mag is enough to start the engine if the coil is strong. The reason a second coupling was not installed was to keep the ercoupe reliable and safe, because if one impulse coupling should fail, it would sure be very unwise to start the engine if little bits of coupling fingers have fallen into the gear housing.
And that makes a lot of sense to me because it sounds like one more thing that Fred Weik would have thought of already.
Furthermore, If I did try to put an impulse coupling and short drive gear on the right side, that gear is expensive and not easy to find. The coupling is even harder to find but can be substituted with a Bendix coupling. However, as the part number does not match, it would not be legal. (It does fit however.)
So here is what I have learned in a short time and have the parts on order to rebuild my mags. I have taken one to pieces and found that they are dirty inside, the points need replacing, the seal needs replacing and everything else has been cleaned up to as good as new condition.
I will leave my right mag as it came, without an impulse coupling, and keep on flying my Eisemanns.
Any further advice on this subject is always welcome.
I LOVE learning from other people's mistakes.
Alan Fairclough.
N87333
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