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Honda BF 60 A ignition problem.

Snoekkop

Contributing Member
Hi gents,
A happy New Year to all.

im having an issue with one of my outboards.

The issue is that i had no spark on one cylinder, i swapped coils from one outboard to another and the issue went away.

tested the coils resistance and all gave me 2.5 ohms on the primaries and within spec on the secondary( 11900 K ohms).

i then removed the resistor in two of the coils( 2 and 3), installed them back and the problem went away.

will it cause any issues by removing the resistor and installing a piece of copper wire to get continuity or will it be ok?

Other than reducing noise interference , what does the resistor do in the cap, as the outboards run resistor plugs , it should filter the RFI , shouldnt it?

Do you think i should replace all the coils? The problem is the waiting for parts.

Your assistance is highly appreciated.

Cheers.
 
I can't answer your question with any authority but personally I wouldn't "futz" around with the resistors. I say that because one of the components that the RFI could interfere with is the ECM if you choose to introduce an unintended (engineering wise) short by using a copper shunt to ground. Not sure why you wouldn't choose instead to replace suspect resistors with some you might easily find online that you could probably obtain much faster than new coils.

I'm a retired fleet mechanic and vehicle maintenance instructor. There are many narratives about failing COP ignition coils taking out the coil drivers in automotive ECM's. My lab scope diagnosis time is pretty limited so I don't have experience or expertise enough to tell you anything other than resistance readings can't always tell you everything you need to know about ignition coils and how they function.

Just my opinion.

Good luck.
 
I didn't realize it was that common an issue, where the RF takes out/screws with the signal firing the plug. That problem about drove me nuts one summer on a Johnson 40 a few years back. That motor ran beautifully with non resistor plugs in it - until it got to 4150 rpm. At that point it would stutter, like it was hitting an rpm limiter. Took me WEEKS to figure out it was the plugs.... Lesson learned here.....
 
I can't answer your question with any authority but personally I wouldn't "futz" around with the resistors. I say that because one of the components that the RFI could interfere with is the ECM if you choose to introduce an unintended (engineering wise) short by using a copper shunt to ground. Not sure why you wouldn't choose instead to replace suspect resistors with some you might easily find online that you could probably obtain much faster than new coils.

I'm a retired fleet mechanic and vehicle maintenance instructor. There are many narratives about failing COP ignition coils taking out the coil drivers in automotive ECM's. My lab scope diagnosis time is pretty limited so I don't have experience or expertise enough to tell you anything other than resistance readings can't always tell you everything you need to know about ignition coils and how they function.

Just my opinion.

Good luck.


Thank you,for your help.

I have tried to get new resistors ,but cannot seem to get them ,even online.

Maybe you can direct me in the right direction,as to where to find them.

I ran the outboard yesterday on a 10 hr fishing trip and had no issues,touch wood.

But as you say resistance measurements arent allways revealing of possible other underlying issues.

I even tried swapping out ECMs and checked all groundings and found that changing ECMs , the issue persisted.All grounds are good.

Checked plugs using a multimeter and got 4.7 Kohms on all plugs in the centre electrode.The "good" outboard plugs measured exactly the same.

I suspect the coils are maybe weak on the secondaries , therefore not generating enough voltage to overcome the combined resistance of the caps and plugs,thats why i removed the resistance at the caps and kept the same resistor plugs. Im no expert when it comes to outboards,but am mechanically inclined,the problem is that where i stay,there is no honda agents , only yamaha and suzuki.

Spares are like chicken teeth, i ordered the timing belts and tensioners from Impex in Japan, i tried to get 3 new coils , but due to civid they are not taking any orders, boats.net dont do shipping to Namibia , where i stay.

My reason for approaching you guys, is that there are very knowlageable guys on this forum that might assist me .thats why i ask for help,dont want to cause any further problems down the line.

I thank you all for the help.
 
Hi,

I have never worked on one of these outboards nor do I have any service information to refer to so, regrettably, I doubt that I can be of any help to you.

Here, in the U.S.A. I can probably just order resistors and other electronic components from Amazon.com but I have no idea what it might take to get something shipped to Namibia. So I can certainly see the difficulty that you are having in the face of the covid lock downs.

Just wondering though if you actually need to purchase or replace anything. You stated that you swapped coils from the good engine and the problem went away. You go on to say that you removed two resistors from the caps (2 and 3) and then put them back and the problem went away. Is that accurate?

If so, then it seems highly possible, at least to me, that you might just have a connectivity issue. I think we all know how corrosion is a constant cause of problems in the marine environment and especially when it comes to electrical connections.

If you unplug a component, plug It back in and a problem gets "fixed" that typically means that you probably improved the connection by doing so.

Could it be that some good contact cleaner like DeOxit and judicious applications of dielectric grease to those connections be the solution?

Are you in the habit of applying dielectric grease to your spark plug boots too? That grease is great at keeping moisture out of the cap and away from the plugs.

I always think and say "clean and shiny" when addressing ANY electrical connection and that is especially true on boats.

I would do some careful inspection and cleaning of those connections should the misfiring recur but, again, I would not "re-design" the way the coils are assembled. Are you positive that those are resistors and not capacitors? Many coils use capacitors to suppress EMI spikes and RFI. Sometimes a quick resistance check might make you think a capacitor is a resistor if it looks like one. Just wondering.

Hopefully this virus will run out it's course soon you will be able to get parts IF you need them.

Best of luck to you.
 
Last edited:
Hi gents,
Update on ignition issues, i have ordered coils for both outboards.

delivery should take 5 weeks or so.

Will update after i install them.

One other question: I have the wiring diagram for the BF 60 A LRTD , and it shows constant 12 V supply to primary via the main relay and switching ( to ground) is done via the ECU.
Is it possible that there could be an issue at the main relay?

TIA
 
I haven't memorized the schematic, but it would seem to me that the master relay would affect all 3 coils similarly? If you have just one coil dropping out on you, I think it safe to say the master is fine.
 
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