Logo
FULL SITE MENU

Honda 9.9 (BF9.9A) No spark unless I disconnect and reconnect the coil.

C

capjls

New member
Strange issue. I bought a used Honda 9.9 over the winter. The seller said he had serviced it and it was running well. I went to test it and could not get it to start. No spark. I checked the kill switch, the wiring, the plugs, then I removed the coil. I put the coil back in and it started right up. A few days later I went to start it and again, no spark. I removed the coil and put it back in and it started on the first pull. I have repeated this 4 times now. I have no idea why I need to disconnect the coil for it to start working. I have video proof, but I guess I cannot upload that here.

Any ideas?
 
Hi,
That's a new one on me.

I assume, when you say coil, that you are referring to the ignition coil not the exciter coil under the flywheel.

One thing I have seen before is that, if you look inside the spark plug boots at the end of the wire, it can get corroded and cause spark problems. They actually get a rusty look to them. I thought cleaning them would help but they kept giving me problems and the rust look would come back. So, I ended up replacing the coils on those two outboards. But, after I thought about it, I wish I had tried just replacing the wires first. Honda doesn't sell the wires separately but the caps (boots) are available and I'm pretty sure I could have McGivered some automotive wires to work.

Not saying that's your problem but it's all I have at the moment.
 
I suppose you could have a broken wire in the harness and unplugging and re-connecting causes it to gain some temporary continuity.
Load testing the wires might provide an answer.

Good luck.
 
Another broken wire theory: what if the primary coil winding wire is separated internally from one of the posts that the harness connectors push on to? Unplugging and re-connecting the harness causes the contact to be good again for a while.

Try ohm testing the primary winding while gently manipulating the posts side to side and up and down. If the reading jumps around or be goes open then the coil probably needs to be replaced.
 
Thanks for the responses. I ohmed it out while moving the posts (they did not move) and the reading stayed steady.
I have been able to reproduce this 2 more times, but not today. I cleaned the posts and the connector, but nothing. I do get a jump on the wires to the coil when I put my meter on the primary side and pull the cord. At this point I think I am going to change the coil.
Thanks.
 
Well, you mentioned ground wire in the video and THAT is where I would focus BEFORE ordering a new coil.
I think you're moving those wires enough that it's reestablishing a connection.in some manner.

First one handed coil r&r I've ever seen though. Doesn't it bolt down in there? That makes me suspicious too.

Good luck
 
Thanks for the advice. Nothing seems to work (I even tried a new coil). The only thing that will make it start is by removing and reconnecting the wires to the primary side of the coil. Sometimes it does not need this, other times I have to do it twice. I ordered a manual and studied the schematic. I thought it might have been a grounding issue, but no. I am wondering about the CDI or the exciter. But, once it starts, it runs great. I had it running for over an hour without a single sputter. I'm going to try it on the lake next Monday, I hope it does not strand me.
 
Pretty strange. I've never seen that before.
I wonder what would happen if you unplugged the CDI connector and used contact cleaner on the terminals in it?

I think I might try that using a can of DeOxit.

Is there cell service on that lake?

Good luck and I hope you don't get stranded either.
 
I did use contact cleaner on the CDI connector. No affect.

Well, it was windy on the lake. To windy to fish. The motor worked, but only after my ritual of disconnecting and reconnecting the coil. I am going to determine if I only need to disconnect one side, perhaps I can put in a remote switch so I don't have to take the cover off each time.

Thanks for the help.
 
Well...not much help but moral support at least.

Here's a thought:
I wonder if this might have anything to do with "residual magnetism"?

I'm a vehicle mechanic by trade and I remember that we used to see old car's ignition distributors get magnetized over time and fail to work. The solution there was to simply replace the distributors. It got to the point that the rebuilt parts stream got "infected" with them. If you opted to get a "re-manufactured" one from a parts store, you had to make sure it hadn't been magnetized in it's previous life.

I'm not sure how that would translate to your outboard but just tossing it out there for discussion.

I once had a sprint car mechanic say to me "anybody that tells you they know EXACTLY how a magneto works is grossly misinformed". I can only assume he knew something most of us do not.

My GUESS is that something is probably wrong with your CDI but it's ONLY a guess. I have never been able to reliably diagnose one using the ohm charts in the service manuals.

I hope you can get it sorted out. Your switch idea might just get you by.
 
Back
Top