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Smoked my CDI 2004ish BF50a... Help please.

C

CaptKen86

New member
It's fitting the Odyssey is coming out this summer, I'll feel like I be able to make my own movie after I get this boat on the water after a season off.

Including a quick history of recent issues in case that has any bearing.

Started with no start, found corrosion in the positive battery line, fixed that. Still no start, but able to jump the and it would turn over. Also no response from remote trim button. Pulled the remote control box. As I was pulling it, trim and start worked. Went to put it back together and it stopped working, ended up taking it off completely and testing everything, found a small pinch/partial break in one of the black wires, fixed it and got it going again. Running fine with no issues when the control box was still open and only connected to the main harness (instruments not connected).

In the past, I had issues with the 10 amp fuse blowing after starting (ran fine, but had to replace the fuse for every start). Took it to a mechanic and he said it was something with the tach and left the tach disconnected. Since I had everything apart, I checked the tach input and it seemed to be working ok. I thought maybe it was the pinched wire I fixed. Went to put it back together and the fuse blew again. I disconnected the tach and put in a new fuse. Fuse didn't blow in time and the CDI started smoking.

I can still start with a new fuse and the CDI heats up until the fuse blows or I pull it. So... I can get it running to try to do some testing if I need to.

Read something about the voltage regulator/rectifier possibly putting out too much power... Gonna try and check that before I put in a new CDI.
 

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Hi,
Sorry you haven't gotten any responses thus far. I don't have the wiring diagrams for a 50A so I was hoping someone with experience on this outboard would give you some ideas.
I did look up the charging coil assembly and see that the CDI and charging system for the 50A and 20D, while not the same, are similar enough to one another that I think some conclusions about them could be drawn. I do have the diagrams for the 20D

But first and foremost, I see that the CDI for the 50A is unavailable/discontinued. I checked both boats.net and yumbo.com in Japan. While you may have an alternative source for one (ebay maybe?) Your should do your best to try and figure out why the CDI "smoked" and is getting hot before considering plugging in a replacement. You will be very disappointed if the "new" CDI smokes too. Not to mention the cost and possible difficulty finding another one.
 
jgmo said:
Hi,
Sorry you haven't gotten any responses thus far. I don't have the wiring diagrams for a 50A so I was hoping someone with experience on this outboard would give you some ideas.
I did look up the charging coil assembly and see that the CDI and charging system for the 50A and 20D, while not the same, are similar enough to one another that I think some conclusions about them could be drawn. I do have the diagrams for the 20D

But first and foremost, I see that the CDI for the 50A is unavailable/discontinued. I checked both boats.net and yumbo.com in Japan. While you may have an alternative source for one (ebay maybe?) Your should do your best to try and figure out why the CDI "smoked" and is getting hot before considering plugging in a replacement. You will be very disappointed if the "new" CDI smokes too. Not to mention the cost and possible difficulty finding another one.
Click to expand...
Thank you, exactly why I'm here. My son graduated yesterday, so I haven't had a chance to dig into testing the voltage regulator or rectifier yet.

Fortunately, the CDI is still functional enough to get the motor running and it seems to take a few seconds to really heat up before it starts to glow. In theory, I should be able to start the motor and pull that 10 a fuse a few more times before I completely kill it. It will stay running without the fuse in place.

Barring that, I'm in new motor territory. Anyone out there got a 70-90hp they want to get rid of?
 
Well, I would suggest a different method of troubleshooting why the fuse is blowing.

If you have a multimeter and a jumper wire you can use to supply 12 volts to the fuse, you could possibly unplug the CDI completely and diagnose why the fuse blows or if it will blow with the CDI disconnected. I don't know of a CDI that's fed voltage from a fuse.

Do you know what that fuse is supposed to power?

I see three 10 amp fuses listed on the parts page. 2 "blade" type and 1 inline glass type. See items 39 and item 38 (lower right corner of page)


For reference, in addition to the 10 amp fuses there are two 15 amp blade type fuses. Items 40 in link.


Sorry, not having the wiring diagram I'm at a disadvantage coming up with suggestions.

Fuses burn most of the time because the power going through them travels directly to ground through a "short" to ground instead of going through a "load" first. And as far as I know, no fuse should be supplying power to the CDI so that is a clue in my opinion.

The CDI should only be powered by the exciter coil and the pulser coil (under the flywheel) that energizes and controls the ignition system components. And, to my knowledge, no fuses are associated with the ignition system.
If your outboard has the "auto choke" (called "service enrichment" or SE) there's also a coil producing voltage for that but, again, that power isn't directed through the CDI and there's no fuse associated with that system.

A common thing that can be found on second hand bought Hondas is that people have been working on them and have crossed the wires accidentally. Most of the wires are color coded and pass through a plastic holder located atop and center rearward of the engine. In that holder, the wires have "bullet" style push in connectors to make replacing components easier but it can also lead to plugging them back in wrong too. Take a look at those wires and make sure there's no mismatched colored wires in that holder.

Wish I had better info for you.

Good luck.
 
Does this help? I will double check the wires around the CDI and the remote control box.

And I am not sure what the fuse powers as well. I could have sworn All I know is that after it blows, I lose the remote controls... No start, not tilt control. Weirdly, the tilt control on the motor still works.

As it is, my plan is to try to get it figured out before I totally melt this CDI, and then order a new one (hopefully).

If not, I was looking at a Honda 75 nearby and might trade this one in on credit.

That would open a whole entire new can of worms I'm not sure this forum can handle... I'd love to hear if you have any tips on keeping my wife's fuse from blowing when I bring up the topic of a new motor. Sometimes it seems shes kicking out a few extra amps when I talk about boat expenses. Short circuiting rapod
 

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Well, we often need the ladies to pull back on the reins and help us slow the roll. But I remember finding the bass boat of my dreams one day, calling my wife and asking her to hurry and bring the check book. To her credit, she came right away and I got the boat. We had some of the BEST times together in that boat but she never failed to tell the story about how I DEMANDED she bring the check book. So, I guess perception is everything.

While the diagram appears to be fairly well illustrated, I can't find any fuses on it except the 15 amp main fuse.

Some things it does show is a "trim control unit" and a trim angle sensor. Is your outboard adorned with that bit-O-kit? I haven't run across trim sensors or trim meters but I have read that they can cause problems.

Again, I say trying, at least once, unplugging the CDI and directly powering that 10 amp fuse with a jumper to see what it does is something that could yield useful info without overheating your CDI.

Doing what you've been doing makes me believe that the CGI is simply acting as a LARGER amperage fuse and is bound to blow any minute. Given that it works to power the ignition, would have me wanting to save it and have it around as long as possible while I figure out what the fuse feeds and try sorting things out that way.
 
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