Looking for some old school Electrical Ignition help.. (ie pre-computer controlled stuff).. Working on a small twin cylinder 4 cycle engine that used the "Waste Spark" setup for the ignition (where both cylinders fired every time whether it was exhaust or compression stroke). I think the coil pack thats on the engines gone as itll run for 2 minutes and die.. you can smell its getting gas.. let it sit for an hr.. itll fire up again and do it all over again...

Bad thing is the mfg discontinued the coil and now they want 2 arms and a leg for the replacement... which i dont feel like paying that much for.. So figured id try going old school and wiring 2 canister coils together to serv the same purpose.. the downside is i wont be able to use their ignition module either.. having to work around it too (iow removing it for my own)..

Excuse my crude electrical drawing.. im not a Picasso...



So was wondering if this would work for getting both coils to fire at the same time? this diagrams showing them wired in series.. but was also thought about wiring them in paralleled.. but not sure which would work better for what i need it to do..

i would wire the coils in parallel for a cleaner cirruet cut. its possible that series could but feed back into the second coil
i dont see why this wouldn't work (flywheel magnet and coil trigger gm hei modual, that drive both coils) , but can we get some pictures, i used to work on a some small engines and it helps to see what the manufacturer used.

Lorddurock said:

i would wire the coils in parallel for a cleaner cirruet cut. its possible that series could but feed back into the second coil
i dont see why this wouldn't work (flywheel magnet and coil trigger gm hei modual, that drive both coils) , but can we get some pictures, i used to work on a some small engines and it helps to see what the manufacturer used.

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will try to when i get a chance.. wont be home till late tonight and going out of town right after work for the weekend so wont be till next week. Then engine itself is a 295CC Robin Engine.. Depending on the year its anywhere between 9hp and 13 hp.. but can never find where that changed.

of what i can find on the pickup module it seems to look and act more like a cam/crank sensor than a magnito. but not sure there..

That will work. make sure to put a heat sink on the hei, it will get hot and burn up.
I use the ones from the back of old tv's.

dustybumpers said:

That will work. make sure to put a heat sink on the hei, it will get hot and burn up.
I use the ones from the back of old tv's.

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i was going to mount it to a plate of aluminum i have just laying in my garage.. that seems to be what they make the distributor housings out of so figured a plate of it would work too..

Sparky83 said:

will try to when i get a chance.. wont be home till late tonight and going out of town right after work for the weekend so wont be till next week. Then engine itself is a 295CC Robin Engine.. Depending on the year its anywhere between 9hp and 13 hp.. but can never find where that changed.

of what i can find on the pickup module it seems to look and act more like a cam/crank sensor than a magnito. but not sure there..

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looks good from my findings, BUILD IT!!

just to make sure for wiring in parallel instead of wiring + to - like in the diagram id instead do jumbers from + to + and - to - right? or would they need to be totally separate leads?

Jumpers are fine. And if you did wire them in series you would have a very weak spark as each would only see half of the supply.

so wired more like this instead??

You dont need the second lead from the + to the coil

DNFXDLI said:

You dont need the second lead from the + to the coil

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you mean from the battery?? but wired in that fashion??

Sparky83 said:

you mean from the battery?? but wired in that fashion??

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Yes and yes

Cool cool. Now i just need parts.

2 msd blasters

Sparky83 said:

Bad thing is the mfg discontinued the coil and now they want 2 arms and a leg for the replacement... which i dont feel like paying that much for.. So figured id try going old school and wiring 2 canister coils together to serv the same purpose..

Click to expand...

Wonder if you could just find some other coil that would interchange close enough and save yourself some effort?

Seems there's a cheap Harley Davidson coil that's a functional replacement for the waste-spark, dual output coil in my BMW. Just another thought...

Lorddurock said:

2 msd blasters

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actually i was going with accel.. cheaper..

john112deere said:

Wonder if you could just find some other coil that would interchange close enough and save yourself some effort?

Seems there's a cheap Harley Davidson coil that's a functional replacement for the waste-spark, dual output coil in my BMW. Just another thought...

Click to expand...

common change over is to a GM twin post coil pack.. but the same ones that tried interphasing with the stock equipment have had nothing but issues.. i suspect their issue is due to poor voltage deliverance to the coils through the stock wiring...

any of yall think the 2 coils would be too much for the control module?? friend of mine was thinking itd be too much for it to handle..

Coil don't take much voltage in, it's what comes out......

You should be fine.

was hoping so... thought maybe they were just scared...

i wanted to give this some though before i posted. im with dusty bumpers. you should be fine. the voltage will be system but the current (A) should be low based on the reseitve design of the coil. the module should be able to take the current of 2 coils wired in parrel.