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'08 Honda BF40A no spark?

Ruggybuggy

New member
This is a new to me '08 Honda 40 4 stroke with remote. I purchased the motor just before winter to put on my pontoon boat. I purchased the motor from a marine dealer in MN which is about 200 miles from me. The motor did come with a 50/50 warranty. I installed the motor on my pontoon and installed the wiring harness they provided. Cranked it over and no start. Check for spark and nothing. I have a wiring diagram but no shop manual. I checked for power at the ignition module (black/yellow) and have power. I check the stop input on the ignition module. This wire (black/red) will stop the motor if it receives a ground signal. No ground found. Also ohmed the the crank shaft signal wires and was 8.1 ohms and it did produce an AC voltage when the engine was cranks.

So does it look like a ignition module or is there something else I should be checking? Are the 40p prone to ignition module failures. I'd ate to drive 200 miles back to them to have it repaired.

I do have this posted on iboats as well.
 
I am a little confused. You said that you have a 2008 BF40A. The 40A indicates that it is a carbureted motor. In 2008, Honda introduced the fuel injected 40D.

Which one do you have? Carbureted or Fuel Injected?

Mike
 
How are you checking for spark? Are you using a timing light or pulling the plug and using a spark tester? If you're going "visual" you might not be getting reliable information and those cheap spark testers can be difficult to get accurate reading from and have actually been known to contribute to ignition module failure when used incorrectly.

I'm going to take a S.W.A.G. at Mike's question and assume you have FI since you mention a crank sensor. Do you know for sure that the injectors are pulsing and she's getting fuel? Have you tried "artificial" enrichment using carb spray or propane to see if it might not be a fuel delivery issue?

Mike is the go to guy here but these are pertinent questions he might need answered in order to help you.
 
Motor is a carb model. It's a 2008 40hp. When I refer to the crank sensor I'm refering to the ignition pulse generator on the crankshaft. Definitely no spark. There is no power at the coils primary windings. Spark was tested with a new spark plug properly gapped held to the side of the engine while cranking. I also did test all three camshaft sensors and all produce AC voltage (6V).
 
I never could successfully see spark in a spark plug when holding it against the block. Maybe it is just me and my old eyes.

No voltage at the primary to the coils is a little more definite.

Before blaming it on a bad ICM, there are probably a few other things to check.

Make sure that the black lead at the spark coils, exciter coil and pulser coils all are truly grounded.

Check the continuity of the other leads from the spark coils, exciter coil, and pulser coils are good to the connector that is plugged into the ICM. Remove the connector from the ICM to make the tests. Back probing into a plugged in connector can give false readings.

Check the black/red lead (stop lead) has no ground at the ICM connector. It could have picked up a ground somewhere in the wiring harness, etc.

Also, check the black/yellow lead at the ICM for 12v, when the key switch is on. I think this lead is for the benefit of the warning lights and probably does not have anything to do with the running of the engine....but check it to be sure.

Check the resistance of the exciter coil 7.02 -8.5 ohm
Check the resistance of the pulser coils 288 -352 ohm
Check the resistance of the spark coils .19 -.23 ohm primary 2.8 -3.4 K ohm secondary.

Checking for voltage normally should be done with a peak reading voltmeter. However, if you are not getting any voltage at the primary side of the spark coil, even a simple meter will tell you that. Try your voltage readings on both ac and dc. Not knowing what kind of meter, it can make a difference in a reading or no reading.

Mike
 
Thanks Mike for the information. I did further testing since my last post using an OTC Genisys. No ground found on red/black at modue connector. Tested the "crank trigger" and was 8 ohms and produced 15V AC whie cranking (if memory serves me correctly). Tested the three camsaft sensors and all produced 6V AC. Black/yellow shows on the wiring diagram as bat +. I have 12V while engine is cranking. Black wire at module shows ground as should be.

I got a call from Honda today and was informed my motor is still under warranty and to bring it in so they can do the repair, got to love it.
 
Would a overheat reg/rec cause the problem. I have one 97 BF40a that will run a few seconds, then die as if kill switch engaged. Ckd. All and reset grounds but same result. Gas is flowing properly
 
Hi,
I don't know this outboard but I can say that, on a Honda, the ignition system and charging system are pretty much isolated from one another on the carbureted models so I would doubt a regulator/rectifier problem would kill the engine like that.
Too bad though that the OP of this thread didn't return to post what the FIX was for his issue.

In many cases like this I often first suspect vibration for causing a poor connection to get worse. Engine stops....connection is re-established and engine starts only to shut down again.

I suggest looking at wire(s) coming from the exciter coil under the flywheel and pulsar coil at camshaft.

Unplugging and reconnecting (CAREFULLY) connectors for those coils as well as the CDI will sometimes cause the problem to "disappear" or change.

The wire harness from outboard to remote can chafe and rub and cause issues. That can be very difficult to track down. Some of those harnesses were not installed or secured well and most boats flex a lot more than cars do. That can be problematic, especially on aluminum hulled boats where an exposed wire can instantly find ground.

I wish you good luck with it.
 
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