2013 Honda 9.9 four Stroke wont stay running sometimes.

Good morning,

I have a 2013 Honda 9.9 four Stroke BABJ (BF9.9DK3 SHA). I bought this motor used and put on a brand new carburetor, changed the oil and the water pump, flushed the gas tank and added new non ethanol gas, changed the spark plugs (CR5EH9). Two weekends ago the motor was running fine and just died. i checked that it had gas, Vent was open on the gas tank, i even open the gas tank lid, but could not get the motor to restart. i let it sit from Friday to Sunday and i figured i would try it one more time before pulling it out of the water and it started on one pull and ran great.

This weekend i ran the motor all day on Friday and Saturday and had no issues. on Sunday i ran it for one mile out and it started sputtering and died. i could not get it to restart. if i waited 30 minutes and tried again then it would start and shut off after 30 seconds. if i waited and hour and tried it would run for two minutes and then shut off. It has fresh gas, hose line is not kinked, gas tank vent open ( and the gas cap). when i squeeze the primer bulb i can feel gas expanding the fuel line after the fuel filter and before the carburetor. when trying to start it when it wont start its not even acting like its trying to start almost feels like a dead engine doing nothing, but if you wait 30 minutes it wants to try and run and if it does start it dies in 30 seconds. I am convinced that after sitting for three days now it will start and run fine, but i am going to have the same problem again at some point. I have not tried to start it yet as the motor is 3.5 hours away from the house and i drive to its location on the weekends. Any advise on where i should start diagnosing this? Thank you. (oil level is fine green light comes on when trying to pull start it, and water pressure coming out the engine is strong) ( I disconnected the kill switch and it still would not start)

Try disconnecting the temp switch, it's on the port side of the cylinder head , two pin plug about half way down. It may be faulty or the engine may be overheating. If disconnecting fixes the problem, see if it is running hot, if so carry out a full cooling system service.

Ok ill give that a try.

Outboard started and ran for 3 seconds. Disconnect temp sensor still would not start. Put spark test light on spark plug, no spark. Checked ignition coil primary resistance. Result was 00.1. Tested ignition coil secondary result was 0.27. Shop manual says the primary should test at 0.35 to 0.43. So new coil?

Use a standard voltmeter set to AC to measure voltage going into the coil from the CDI unit, back probe the wires going into the coil, pull starter or crank if electric start, voltage should be around 100v. If voltage is fine, then yes, replace the coil.This is a far better test than the resistance test described in the manual.

When measure voltage going into the coil do you leave the wires connected to the coil or remove the wires to the coil and probe them with volt meter leads?

Leave them connected

With volt meter set to ACV 750. I'm reading 001 to 002 on the meter. This is from the two wires coming into the coil while still connected and attempting to pull start the engine. Engine did run for two minutes tonight and then died and would not restart. Meter readings were after it died. I also checked the 6A charge coil green to white was good but got no resistance measure reading with grey 1 or grey 2 with white or from grey 1 to grey 2 with green.

Update. I got the motor to run and it was staying running. I wiggled the wire harness that goes to the ICM and motor shut off. Every time I wiggle the wire harness. I pulled all the tape off the wires and the short doesn't appear to be at any of the terminals at the ICM, but may be in the middle one of the wires. I tried wiggling one at a time but I have not isolated it done to the one wire causing the issue. This will be fun.

So the coil is okay, good luck finding the fault. If you have a wiring diagram,unplug the CDI unit, the coil and the pulser coils. Rig up a 12volt test light ( not LED ) with one end connected to a 12v battery pos and the other to one end of wire you want to test.Use a second lead with a very thin probe on one end and the other to the negative post. Then test each wire wiggling it to see if the light goes out indicating an internal break or a dry joint in the plug.Have fun this is a good challenge!

Just out of curiosity one of the terminals on the wire harness that connects to the CDI was corroded green. I cleaned it with electric cleaner and some scraping. This however did not stop the motor from shutting off when you moved the wire harness. My question is this the wire i should start investigating? would a intermediate short in a wire cause a connector terminal to corrode green? all the other terminals were shinny new looking. I dont know where that wire goes to just yet until i get the tape off the complete wire harness and trace the wire. The wire is all black and the CDI has three all black wires ran to it. I could not find a terminal identifier in the shop manual of what each pin was responsible for. I only see a resistance table on how to check the CDI.

Black will cause the problem, one goes back to the exciter coil which charges the CDI, one goes to the pulsar coil which triggers spark, and the third goes back to the main earth on the engine. So very definitely, black being corroded will be your problem.

Problem solved. The black wire on the CDI ( rights side second from the bottom) had a short at the connector terminal. This black wire ran up into the wire harness and then split into three other black wires one running to ground, one running to the kill switch ground side, and one went somewhere else i forget. I removed the terminal from the connector and removed the wire from the terminal. I cut off 5 inches of the original black wire and butt connected a new 5 inches back on and then solder the terminal onto the wire as i didn't have a matching new terminal laying around.

Engine ran fine and would not shut off no matter how much i wiggled and pulled on every wire. Taped everything back as manufactured and good as new. Also it was the same wire that had turned the terminal connector green inside the CDI wire connector. I also noticed that when i stripped this wire back the actual copper wire was starting to tarnish inside the rubber coating.

After finding the problem i realized that the majority of the time this motor would shut off on me was coming from 3/4 throttle to an Idle speed. When this engine goes from throttle to Idle it tends to have a increase in vibration just before coming to Idle. This vibration ( Shaking) was just enough for the ground wire to the CDI to loose connection, and if it did not regain connectivity then the engine had no spark and was dead in the water. So if your engine dies when coming off plane and right when it gets to Idle speed. check the ground wire at the CDI connector.

well done, you just saved yourself a heap of money,this is the sort of fault that is time consuming to solve, even for someone who works on them all the time.

So, this wire....was it part of the new harness you installed?

At any rate, really glad you got it! It really had me scratching my head as to what it could be since you said it had good spark but it wouldn't fire on engine killer!

Instead of starting fluid, please look into using propane gas as a substitute fuel for troubleshooting. Much safer for you AND your engines!

Happy boating.

jgmo said:

So, this wire....was it part of the new harness you installed?

At any rate, really glad you got it! It really had me scratching my head as to what it could be since you said it had good spark but it wouldn't fire on engine killer!

Instead of starting fluid, please look into using propane gas as a substitute fuel for troubleshooting. Much safer for you AND your engines!

Happy boating.

Click to expand...

Good morning.

I think you are confusing two separate Issues. Yes this wire was a part of the new wire harness and it did solve that issue at the time. That was back in July. However today it wont start at all. It has fuel and spark.

Oh! Yes, sorry. I got mixed up on this one.

With spark and fuel and timed correctly I'm at a loss aa to why it refuses to start. If you were a shop you would have a known good CDI and Pulsar to try. It could be that one of those modules is "breaking down". But it's just too costly to buy new ones until all else has been checked out first.

I do NOW suspect that the problem may still lie in that new wire harness. You did a good job explaining how certain harmonic vibrations (of which these engines have an abundance) would cause that connection to momentarily fail. It seems to me that something very similar may still be going on with that harness. Either that or there is a connection, possibly a ground, that is losing conductivity in a similar manner.

In vehicle repair it's common for a tech to use jumpers to add ground wires or power wires to prove out a circuit when conductivity is suspected. We call it "overlaying" wiring. Often the overlay wire is simply left in place if it solves the problem rather than completely replacing or repairing the existing harness.

I would be going through all connectors checking fit and tightness along with a dose of DE-OXIT electrical cleaner. Then I would move on to mechanically tightened connections, such as grounds held with screws or studs, making sure all are clean and tight.

After that the overlaying of wires, one circuit at a time, might be something you'd want to try.

Obviously this is frustrating, tedious work but can be necessary to track down the gremlins that are keeping you off the water.