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2005 BF75A5 only firing on 1st and 3rd cylinders

J

joeyc

New member
Hi Folks, I have a new-to-me 2005 75hp carb'd outboard that is only getting spark on 1 and 3 cylinders. Motor hasn't been run in at least a year. The wiring diagram from Honda site shows that one coil feeds the 1 and 4 plugs and the other coil feeds the 2 and 3 plugs.
Any thoughts on this situation would be greatly appreciated!
 
That's just plain weird. Probably going to have to drag the service manual out and do some trouble shooting here.....

I would likely start by confirming the info you found on line.
 
Alan Hicks said:
That's just plain weird. Probably going to have to drag the service manual out and do some trouble shooting here.....

I would likely start by confirming the info you found on line.
Click to expand...

Alan, it is weird! Here is a pic of the wiring diagram.
 

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    ignition wiring.png
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Just a guess but I would check for poor/corroded connections in the 4 wire driver plug at the ignition module.

Good luck.
 
Well, it's a long shot but you're welcome.

If the coil fires one cylinder it should fire the other but electrical resistance can cause strange problems.

I would also suspect high resistance in the plug wires might cause this and I wouldn't rule out bad spark plugs in the dead cylinders either. You might try moving plugs and plug wires around to see if anything changes. If the problem follows the component, you may have an answer.

Again,
Good luck....we're pulling fer ye!
 
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