Can anybody give me the low down or first hand experience on connecting a tach to a magneto electrically? I've been led to the signal converter that Auto Meter sells, but my mag re-builder says it not possible to take a reading from the earth stud. Some modern tach state they are compatible with a magneto (Very rare and Expensive) and some say they are compatible with ANY ignition system, then when you ask if it will work with a magneto they don't know! I haven't got a tach drive on the mag or the space to fit a drive off the crank which is why it needs to done electrically.
not much help here....but what about running off the back of the generator i know there could be some slip but wouldnt be terrible I'd think just need to have equal pulleys or a gearbox of some sort good luck Zach
Do you have access to quality electronic measuring devices, or friends with such? Big stationary engines use the funny extra terminals on alternators for speed signals, you get some kind of electric signal speed synch'ed to the engine, could be one to one, two thirds to 18 etc. So if the only terminal on the Mag is the earthing terminal, try it see what's there and how strong. Last chance would be to place a magnetic pickup somewhere to count flywheel teeth or something to represent speed. you will need to drill and tap. Try Atlantic Diesel Lodi NJ.
I ran a couple different "tach adapters" on a Vertex magneto. They SORTA work. At low RPM's they are somewhat sporadic - my guess is that is a result of electrical noise issues - just a guess. bottom line - it really didn't work all that well, but was better than nothing.
I've gone down this route before. Theres just to many ifs and buts. I've read with the signal converters that you should run suppression leads. Shouldn't really use suppression anything with magnetos.
Check with Auto-Meter and see if you can pick a signal up off their Pro-Control Rev Limiter that will work with a mag. I have one, but currently using the tach drive off my mag. Might be cheaper than some of the other things mentioned.
Don't bother, get a mag with a cable drive if you want numbers. I have the Autometer signal converter with a vertex mag and I might as well piss in the wind.
Hi Clark, When i was running a vertex mag on the flatty i used a magnetic pickup on the front crank pulley and had the rev counter converted. There is a company in Wales who will supply the pickup and will convert any rev counter to except the signal. Just give us a shout and i will dig the number out for you.
http://www.speedwaymotors.com/p/2666,771_Tel-Tac-Tachometers.html this is the tack my friend uses in his sprint car
The Auto-Meter Signal Converter is a POS. I biught one new and was excited. I had solid core wires, like you're supposed to run with a mag. Needle on the tach went wild. Called them and they said ya' need suppression wires. Changed'em out. Little if no improvement. I bought the correct memory tach from them and I've been OK ever since, even with the solid core wires. Auto-Meter was willing to trade me product in exchange for the signal converter, so that tells me they know it's not the hot set-up. AND ................ make sure ya' get the correct tach for your mag. There's a difference between the signal coming outa' a mag with an internal coil, external coil. etc., etc..
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