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Martin

onan coil bad, harley coil replacement.........

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got this 416H from terry (vinylguy) last week, engine had no spark and needed to trouble shoot to determine the culprit. most of the electrical was corroded on the terminals and after a bit of hunting and cleaning, had to replace the ignition switch (terminal almost rusted off) and ordered new 9 terminal molex connections to replace some burnt circuits. the molex terminal blocks and terminals came in today but i still have to get them installed. temporarily everything is working and connecting well but i dont want to leave things that way.

anyway back to the ignition......

 

alright, researched the demystification guide and got a hunting for spark. since this topic is about a coil replacement i will cut to the chase and say the ignition module tested ok, and everything else was working as it should after some tlc on molex terminals to the engine harness and a new ignition switch. the coil resistance on the primary was good, but the secondary was nil.......so coil was deemed bad and needed replacing.

 

since the onan coil is no longer available (exact coil used on this engine) and they do a retrofit kit using a slightly different coil and a bracket to clamp and bolt into position and it runs close to $100 for the bracket and coil, i wasnt really interested in oem. since the tractor mechanicals were still unknown and i already have a bunch of onan parts laying around (even 2 or 3 points coils- which are a different resistance on the primary than the electronic ignition). i know a harley coil can be used on the kohler twins, i have one fitted to my kt17, points ignition though (5 ohm resistance). so i had to look into a harley coil with the primary resistance in the range of the oem, (2.9-3.6 ohms). they make one 3 ohms for electronic ignition so i ordered one off ebay seller gorilla motors.

 

next thing was a bracket had to be made to fit it to the engine. i left the oem coil in the stock position as it sits in a hole in the tins, if removed it would leave a hole there that might affect airflow to the rear cylinder and all onan owners know we dont want to do that. so i decided to mount it using a unused weldnut in the blower housing right next to the spec decal and the bolt that holds the rectifier/regulator in position. this made one spark plug lead short and a new one needed to be used, but everything else bolted up wiring wise. the condenser was moved from the air cleaner bracket and was mounted on the fabricated coil bracket.......

 

 

now comes the fun part......

 

firstly before taking anything apart i made sure to note what wires were connected to the coil. basically the + has the yellow (power from ignition) red (B+ from ignition module) and the condenser lead.....

the - has the black from the ignition module (B-)

 

post-4321-0-83489700-1381882837_thumb.jp

 

heres the bad ignition switch that also needed replacing....

 

post-4321-0-79580600-1381882856_thumb.jp

 

position where im going to put the coil on top of blower housing using bolt from RR and unused weldnut near spec decal....

 

post-4321-0-38045600-1381882872_thumb.jp

 

coil bracket....

 

post-4321-0-15206000-1381882885_thumb.jp

 

coil bracket bolted to engine tins.....

 

post-4321-0-51275400-1381882902_thumb.jp

 

coil being used, harley dual fire, 3 ohm......

 

post-4321-0-76279400-1381882917_thumb.jp

 

i bought this kit of ignition wires just for times like this, under $10 and get 6 wires of various lengths and terminals, boots etc.....

 

post-4321-0-69694500-1381882931_thumb.jp

 

coil mounted up and wiring connected. the front spark plug wire runs from here through the oem routing to the front plug. the primary terminals on these coils are unmarked, and it really doesnt matter to the coil what terminal is which, just designate which terminal you are going to use for + and - and stick to it. DONT MIX WIRES!!!!!! if you take one terminal and call it positive(+), mark it and connect your ignition power (yellow wire+), ignition module red wire (from module wiring B+) and the condenser wire......

THE OTHER TERMINAL ONLY GETS THE BLACK (B-) FROM THE MODULE WIRING......

 

post-4321-0-73853400-1381882948_thumb.jp 

 

post-4321-0-50967300-1381882967_thumb.jp

 

heres a video or two.....

 

th_IMG_2375_zpscbc6b559.jpg

 

another video is on the way....

Edited by Martin

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I used a coil for a Chevy Cavalier on my 420HC.  It was only $17. (some modification required!)

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got this 416H from terry (vinylguy) last week, engine had no spark and needed to trouble shoot to determine the culprit. most of the electrical was corroded on the terminals and after a bit of hunting and cleaning, had to replace the ignition switch (terminal almost rusted off) and ordered new 9 terminal molex connections to replace some burnt circuits. the molex terminal blocks and terminals came in today but i still have to get them installed. temporarily everything is working and connecting well but i dont want to leave things that way.

anyway back to the ignition......

 

alright, researched the demystification guide and got a hunting for spark. since this topic is about a coil replacement i will cut to the chase and say the ignition module tested ok, and everything else was working as it should after some tlc on molex terminals to the engine harness and a new ignition switch. the coil resistance on the primary was good, but the secondary was nil.......so coil was deemed bad and needed replacing.

 

since the onan coil is no longer available (exact coil used on this engine) and they do a retrofit kit using a slightly different coil and a bracket to clamp and bolt into position and it runs close to $100 for the bracket and coil, i wasnt really interested in oem. since the tractor mechanicals were still unknown and i already have a bunch of onan parts laying around (even 2 or 3 points coils- which are a different resistance on the primary than the electronic ignition). i know a harley coil can be used on the kohler twins, i have one fitted to my kt17, points ignition though (5 ohm resistance). so i had to look into a harley coil with the primary resistance in the range of the oem, (2.9-3.6 ohms). they make one 3 ohms for electronic ignition so i ordered one off ebay seller gorilla motors.

 

next thing was a bracket had to be made to fit it to the engine. i left the oem coil in the stock position as it sits in a hole in the tins, if removed it would leave a hole there that might affect airflow to the rear cylinder and all onan owners know we dont want to do that. so i decided to mount it using a unused weldnut in the blower housing right next to the spec decal and the bolt that holds the rectifier/regulator in position. this made one spark plug lead short and a new one needed to be used, but everything else bolted up wiring wise. the condenser was moved from the air cleaner bracket and was mounted on the fabricated coil bracket.......

 

 

now comes the fun part......

 

firstly before taking anything apart i made sure to note what wires were connected to the coil. basically the + has the yellow (power from ignition) red (B+ from ignition module) and the condenser lead.....

the - has the black from the ignition module (B-)

 

attachicon.gifIMG_2359.JPG

 

heres the bad ignition switch that also needed replacing....

 

attachicon.gifIMG_2360.JPG

 

position where im going to put the coil on top of blower housing using bolt from RR and unused weldnut near spec decal....

 

attachicon.gifIMG_2367.JPG

 

coil bracket....

 

attachicon.gifIMG_2368.JPG

 

coil bracket bolted to engine tins.....

 

attachicon.gifIMG_2369.JPG

 

coil being used, harley dual fire, 3 ohm......

 

attachicon.gifIMG_2370.JPG

 

i bought this kit of ignition wires just for times like this, under $10 and get 6 wires of various lengths and terminals, boots etc.....

 

attachicon.gifIMG_2371.JPG

 

coil mounted up and wiring connected. the front spark plug wire runs from here through the oem routing to the front plug. the primary terminals on these coils are unmarked, and it really doesnt matter to the coil what terminal is which, just designate which terminal you are going to use for + and - and stick to it. DONT MIX WIRES!!!!!! if you take one terminal and call it positive(+), mark it and connect your ignition power (yellow wire+), ignition module red wire (from module wiring B+) and the condenser wire......

THE OTHER TERMINAL ONLY GETS THE BLACK (B-) FROM THE MODULE WIRING......

 

attachicon.gifIMG_2372.JPG

 

attachicon.gifIMG_2373.JPG

 

heres a video or two.....

 

th_IMG_2375_zpscbc6b559.jpg

 

another video is on the way....

Thank you Martin, I just purchased the same coil from gorilla moters 3 ohm and should be in by the 8th. I will update after I install it .

   Thank you for your time and information

  Jesse

Edited by Jess
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So what was the cost of this coil?

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So what was the cost of this coil?

 

$35.95 w/free ship. On one of mine i ended up switching the harley coil out and going back to oem, which cost me around $100 with the bracket needed to retro fit the newer style Onan coil. but if you are prepared to deal with the making of a bracket and/or not looking 100% oem then these coils are a cheaper alternative and they work great. i have two running at the moment, one on a kohler kt17 series 2 (5 ohm -for points) and the Onan p216 (3 ohm).

 

since posting links from ebay is out, search for this....

 

 

Harley CHROME Ignition Coil 3 Ohm Dual Fire FL FX Big Twin, XL Sportster 85-99

 

 

i have bought a few of them from seller Gorilla Motors, right now looks like the only ones they have in 3 ohm is chrome. if you wanted black, there are similar looking ones from other sellers but I've noticed none around the $35 mark.

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Thanks martin

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