1986 FJ1200 Flickering Gauges - Possible Charging Issue?

[Bill_Rockoff]

The *battery* terminals might be clean, but those connector blades may not be. Cleaning them might help. I replaced that connector with individual spade connectors, and it has been good for the last 4 years.

[Pat Conlon]

Gabe, you need to verify that the generator is charging the battery.
Run the engine at 3000 rpm while you have the multi tester leads on each pole of your battery.
Report back the voltage.

[iWant2RideMyBike]

Gabe, you need to verify that the generator is charging the battery.
Run the engine at 3000 rpm while you have the multi tester leads on each pole of your battery.
Report back the voltage.

Pat,

I'm sorry it took so long to get back. I was waiting to put the bike back together until I could install my new Choke Cable Assembly from RPM (which I did tonight. It works great!) I actually ended up making a video of the repair, in hopes that it may help another FJ owner out in the future! I'll get it up tomorrow at some point.

So anyway, I ran the bike at 1500rpm first, and the voltage was reading at 15.62, then 15.58, then 15.55, then 15.58, then 15.62, then 15.61, etc... This was happening quite rapidly and it fluctuated back and fourth that way. I took a video of it with the voltage reading visible, and I'll post it for you tomorrow since I don't have time tonight.

Next I rev'd her up to 3000rpm like you asked, and she'd get up to about 15.5 to 15.6 volts. I didn't get the video of the voltage meter at 3000rpm just yet, but what I did capture on video is one of the symptoms that concerns me most. She'll be happy idling at a slightly higher speed (about 1250rpm) with the choke out just slightly after warming up for a few minutes, but then I give her some throttle and she dips WAY down in rpm's. Almost stalls out even. 12.65 volts to 12.75 volts before throttle blip, then 12.21 volts to 12.27 volts or so. If I push the choke in at that point, seeing as she should be warmed up decently, she will most definitely die out.

Once I get those videos uploaded, of her idling and displaying the symptoms, after work, I think my concern will be more clear. I hope that perhaps they can help to uncover what may be happening.


- Gabe

[Tuned forks]

Everyone's gonna warn you about those voltages.  I'm going thru the same thing.  Over 14.7V is going to cook batteries and burn out other things.

Your choke issue sure looks like a vacuum leak.  Smarter minds will set you straight.

Joe

[iWant2RideMyBike]

Everyone's gonna warn you about those voltages.  I'm going thru the same thing.  Over 14.7V is going to cook batteries and burn out other things.

Your choke issue sure looks like a vacuum leak.  Smarter minds will set you straight.

Joe

Joe,

I'm actually trying to upload the videos now. If it completes within the next half hour, I'll put them up. Now that you mention it, If I pull the choke out too hard, the carbs almost seems to make a kind of hissing noise that takes causes the RPMs to dip before realizing "Oh wait, i'm choked, I should probably INCREASE my RPMs! Not drop half a thousand RPMs!" and then climbing up. Do you think taking some good old carb cleaning spray and hittin her around the boots and other areas around the carbs (Save for the pod filters) to see if the RPM's jump would be sufficient to check for a vacuum leak?

- Gabe

[Pat Conlon]

Anytime your bike idles fine with the choke on, only to die when you take off the choke indicates your idle circuits are plugged.
Time to (properly) clean your carbs.

Re: charging voltage: 15.5-15.6 volts is too high. It's common with FJ's. Consider the Transpo voltage regulator modification.
You will cook any AGM or lithium battery so you don't want those types of batteries in your FJ until you fix the voltage regulator.  On a conventional lead acid battery will boil the electrolyte so be sure it is vented properly.

[iWant2RideMyBike]

Anytime your bike idles fine with the choke on, only to die when you take off the choke indicates your idle circuits are plugged.
Time to (properly) clean your carbs.

Re: charging voltage: 15.5-15.6 volts is too high. It's common with FJ's. Consider the Transpo voltage regulator modification.
You will cook any AGM or lithium battery so you don't want those types of batteries in your FJ until you fix the voltage regulator.  On a conventional lead acid battery will boil the electrolyte so be sure it is vented properly.

Man, I knew I'd end up having to take those darn carbs apart and clean 'em up. I can't get lucky!

And as for the charging voltage, I figured you would say that. Here is the video of the bike idling at about 1.5k RPM (with choke engaged) and the voltmeter reading. https://www.youtube.com/watch?v=H58i4ZzSDQE

Here is the video of her idling more nicely with just a little baby bit of choke on, but when I give her some throttle, she nearly dies. Voltmeter visible here too. https://www.youtube.com/watch?v=pULId0ziRSQ

It just confuses me because while the engine does nearly stall in that last video, the RPM's slowly start to increase back up with the voltage, as seen in the video. Electrical work is still very new to me, so I'm at a loss. I will however look into that Transpo voltage regulator modification. I read in another thread that the Bosch RE55 was a popular replacement for the OEM regulator. Any truth to this?

As always, thanks for all your time and help.

- Gabe

[iWant2RideMyBike]

Hello everyone and sorry for going dark for awhile there. Rest assured I've been riding my FJ every single day that I can here. Even when it was 32 degrees Fahrenheit outside earlier this week @ 7:30am for my ride to work in the Twin Cities! Haha, can't keep me down. But I have still been ongoing with this issue and trying to find out the problem. Well, I found it!

UPDATE TIME

While going through a wiring diagram today on my continued quest to figure out this suspected electrical problem, well, I came across a wire I had not noticed was there before. Shout out to Pat Conlon, because that son of a gun was dead on! THE INFAMOUS RED PLUG PROBLEM STRIKES AGAIN!
I looked for the red plug on the left side of the bike when it was suggest, by Pat, that I check it out. I did not find a red plug so I thought that one of my bikes previous owners must have already fixed this. I dismissed it as a possible problem. I was wrong though, the red plug was there. It was just hidden underneath the rear wheel cowl. I was so taken back when I saw it there, borderline disbelief. I wiped it down because it was very dirty, and then I popped her open to see what was inside. Totally toasted alive! Both sides of the plug are messed up, and believe it or not, I'm so happy about it. I now know for a fact that an electrical issue did exist, and I can fix that.

However, I'm not sure what my next step should be. Is there a particular way to replace this plug, or a favorite option for fixing this among the community? Any info is appreciated, as always! (Thanks, Pat, by the way! You were right!) I attached some pictures of the plug too!

[red]

I'm not sure what my next step should be. Is there a particular way to replace this plug, or a favorite option for fixing this among the community? Any info is appreciated, as always! (Thanks, Pat, by the way! You were right!) I attached some pictures of the plug too!

iWant2RideMyBike,

I can't give you a Part Number, but these guys have phone help, and they may know what you need.  Otherwise, maybe somebody here can chime in with a Part Number.  They may need a tracing of the shell to replace it with the same exact connector, but that's not critical.  Just make sure the new connector will have two beefy blade connectors inside, with some sort of keyway design that keeps you from plugging it together in the wrong way.

Here are some sources for vintage electrical connectors of all sizes and types.  Call them, for more assistance.  Ask about any minimum amount of money for an order.  I can always spend more money with what they carry, such as tools, power/fuse boxes, splices, terminal lugs, et c.

http://www.easternbeaver.com/Main/Elec__Products/Connectors/connectors.html

http://www.cycleterminal.com/index.html

http://vintageconnections.com/

http://www.oregonmotorcycleparts.com/connectors.html

http://www.electrosport.com/accessories/connectors-and-wiring.html
.

[Pat Conlon]

Ha! Even a blind squirrel finds an occasional acorn.
Fix the plug but you gotta ask yourself "Why did this happen?"
After the plug fix, take another read on the charging voltage at the battery. If it continues to be 15.5+ volts and the brown generator field wire ohms out ok, then consider a Transpo VR mod.
The melted red plug is a symptom, not the problem.

Cheers

[FJ_Hooligan]

I replaced my red connector with 2 individual clear shrouded spade connectors.  No problems since.

[red]

Gabe,

Once any connector gets corroded, it becomes a resistor (think heating element), not a straight conductor.  A weak or run-down battery can draw a lot of power (heat) through that plug, melting the corroded plug with no other problems.  If the good replacement plug has the fully-charged battery charging at 14 Vdc or more, you probably will need a factory-new or aftermarket-new voltage regulator.  Too much charging voltage can boil a good lead-acid battery to death.  Check the water levels in the battery often, if possible, when you have a charging problem such as too much voltage coming in.
.

[iWant2RideMyBike]

Ha! Even a blind squirrel finds an occasional acorn.
Fix the plug but you gotta ask yourself "Why did this happen?"
After the plug fix, take another read on the charging voltage at the battery. If it continues to be 15.5+ volts and the brown generator field wire ohms out ok, then consider a Transpo VR mod.
The melted red plug is a symptom, not the problem.

Cheers

Pat,
yeah I suppose you're right. I rewired her last night and it seemed to help some, but she did still end up going up to 15 volts and hanging around high 14 to 15.3 or so, with the choke open (b/c its been cold in Minnesota the last few days).

When you speak of the brown wire from the generator, I haven't taken the reading on that yet. If it's sketchy, is this the mod/install you're speaking of? I found this on the RPM website. http://rpmracingca.com/proddetail.asp?prod=Electrical%3ARegulator&cat=39 I'm willing to spend money making this bike a more complete machine, so that really isn't an issue for me, but of course it seems silly to go around replacing parts that don't need replacing. And I'm in unfamiliar territory with the electrical stuff, so that's my fear at the moment.

[iWant2RideMyBike]

Gabe,

Once any connector gets corroded, it becomes a resistor (think heating element), not a straight conductor.  A weak or run-down battery can draw a lot of power (heat) through that plug, melting the corroded plug with no other problems.  If the good replacement plug has the fully-charged battery charging at 14 Vdc or more, you probably will need a factory-new or aftermarket-new voltage regulator.  Too much charging voltage can boil a good lead-acid battery to death.  Check the water levels in the battery often, if possible, when you have a charging problem such as too much voltage coming in.
.

Hey Red,
Thanks for that clarification. I took a class called Micro-Computer Architecture in college a few years back and in that we had training with wiring and setting things up like this, but I have never had to use it since. Most of my knowledge left me, so I'm not very confident about any of this.

[Pat Conlon]

....When you speak of the brown wire from the generator, I haven't taken the reading on that yet. If it's sketchy, is this the mod/install you're speaking of?

Hi Gabe, the field sensor wire is typically the smaller wire that runs with the big red wire (that supplies the heavy generator output) on my bike the wire color is brown, but again it's right next to the big fat red wire.
The purpose of this field wire is to tell your Voltage Regulator (VR) when it's time to charge your battery by reading the voltage of the battery. For example, if the field wire senses 11 volts from your battery, it signals the VR to let current through to the battery to charge it. If the field wire senses 15+ volts at your battery, it signals the VR to stop the current to the battery.
If this field wire or it's connections are compromised, say a bad connection only lets thru 11 volts when actually your battery reads 14 volts....the VR is gonna think your battery needs recharging when it doesn't, thus overcharging your battery. It's not the VR's fault, it's just doing what it is signaled.
Here is more discussion on the subject:
http://www.electronicamotos.com.ar/technical-resources/library/known-issues/street_65300.html

So, fix your red plug, do a voltage check on this field wire. Compare the battery voltage at both ends, at the battery and at the VR. The voltages should be very close to each other.
If the wire is fine, good. If you are still overcharging @15.5+ volts, replace your voltage regulator.
I suggest the aftermarket adjustable Bosch/Transpo VR IB301A. Here's a link:
http://www.fjowners.com/index.php?topic=661.0

IMHO mounting the Transpo VR away from the engine heat and vibrations is a good idea and the cherry on top is the fact that you can adjust the voltage output from the Transpo. I have mine set at 14.4 volts and the output is dead nuts steady at 14.4, never higher. My batteries love this....

Cheers