I am having trouble with a 94 fatboy I bought about 6 months ago. Several things that may or may not be related.
1. turn signals do not flash at higher rpm's. when I let off the throttle, they start flashing.
2. rear cyclinder fouled plug. may be rings but I want to rule out other things first. I replaced the spark coil and plug wires just in case either was starting to break down. Bike seemed to run better after they were replaced. I have only put about 50 miles on it since changing coil, wires and plugs so I have not pulled the plugs to look at them yet.
3. tonight is the first time I rode it at night. I was cruising along at about 55 and it hesitated a little. The lights would then go dim and then get brighter every 15-20 seconds. when they were dim, there was a change in the performance ( for the worse ) not real bad just seemed to lose some power and slight miss.

Any ideas on what could be causing this? Could they all be related? what about stator or voltage regulator. Almost seemed like it was getting too much power at higher rpm's prior to tonight since the signals would not flash until the rpm's dropped. thanks for any hlep or ideas.

 

TO CHECK CHARGING SYSTEM

This bit of info helped me alot when I was rebuilding and troubleshooting all the eletrical deamons on my old EVO Bagger. Hope it helps you test the Stator and Voltage Regulator...


The first thing to check if you suspect a charging problem is the battery and the wires attached to it. If the wires are loose, make sure to tighten them up. If you see any corrosion, disconnect them and clean them off with a wire brush before re-attaching. Check each cell on the motorcycle battery to make sure the electrolyte is covering the plates, if not, carefully add distilled water until the fluid reaches the "top" line on the side of the battery. If your battery is less than fully charged, use a low amperage charger (1 to 3 amps) and charge it until the indicator says it's full. If it doesn't take a full charge, replace it with a new one.

When your wires are clean and secure and the battery fully charged, you can get started checking the system. Perform the following checks:

Battery: Turn ohmeter to the DC Volts setting that can read 12V or more. With your motorcycle off, read from Positive to Negative making sure the Red is +, Black is -- If battery is good you should get about 12.5 to 13.5 volts

Charging: Using same multimeter range, start the motorcycle and run RPM's up to above idle.Voltage should increase to several volts above initial reading, usually to about 14.7 V Voltage should not go much higher than 14.7 V. If voltage goes alot higher when you rev the engine, you could be overcharging due to a voltage reg problem. If voltage doesn't change, your motorcycle is not charging.

Stator: If your motorcycle is not charging, you need to check the stator. Locate the plug for the stator on the front of the engine block. Switch the multimeter to OHMS range on the lowest setting, usually 10 ohms. With the motorcycle off, read between the 2 pins or holes in the block. These should show continuity. If your meter is accurate you could read 1 to 3 ohms, but cheaper meters will not be that accurate. As long there is continuity it passes this test.

Now change the setting on the multimeter to the highest OHM range like 100K. Touch one probe to a pin or hole in the engine, the other to the engine case or a metal bolt on the engine. The meter should not move. Try the other pin the same way and it also shouldn't move. If you get any reading the stator is shorted and must be replaced. If you get no movement on the meter, it's not shorted out so you need to check for output.

To check for output, change multimeter to AC Volts setting over 100 Volts. With the alternator plug disconnected, start the bike. Use the probes (not polarity sensitive) to read between the pins or holes in the engine block. You should read about 20V per 1000 rpm's. At idle expect about 25V, as you rev the engine it will increase to 60 or 70 Volts. If it does your stator is OK, if you get no output the stator is bad and you will need to replace it.


Voltage Regulator: If your stator is not shorted to ground and has the proper output, your regulator is most likely the culprit. If your stator checks out OK but battery voltage doesn't increase when the motorcycle is running, the regulator isn't doing it's job and needs to be replaced. It's an easy swap, just make sure you bring the old one with you to make sure they give you the correct unit. If the battery voltage goes too high when you rev the motorcycle the regulator isn't limiting the voltage and again it needs replacement.




Second way to test:


Step 1. First and foremost load test the battery. Even if it measures over 12.5 vdc it can still be bad under a load. Battery is typically rated at 19 amp hours and 270 Cold Cranking Amps (CCA).

Start the engine and measure DC Volts across the battery terminals, the regulator should be putting out 14.3 - 14.7 vdc at 3600 rpm and 75 degrees F.


Step 2. To check the regulat

 

89FLHT

Thanks for all the info. This will difinitely give me some things to look at.

 

Turn signals need Good voltage to flash.................10 or less volts they wont flash. You are losing volts at higher RPMS. Unplug your voltage reg from the engine block and check the A C volts coming from your stator. Look up the correct voltage for your model, The specks will be for a certain RPM range..........If the AC volts start to decrease when RPMS increase.......The problem lies within the rotor/ stator combo. This is a simple test and is where all your electric begins, I would start here............Dosen't matter what shape the battery is in for this test. the battery is not used. You are measuring AC volts generated by the rotor/stator

 

Thanks for the advise.

 

OK. I had the battery load tested and it is fine. Bike off the battery reads about 13.4 volts. Start it and it jump to just under 15 with higher rpms. Stator and regulator seem to be fine.

Is there any part of the charging system that would only be affected under load. When it is in the garage in neutral, the lights flash at higher rpms and none of the other symptoms are noticed. Everything happens while I am riding and at higher rpms.

Thanks,

[IMG]local://upfiles/19465/5F905278E46E44FB807F16E28EA1CD89.jpg[/IMG]

 

First things first, Saw the pic of your scoot and it's SWEEEEEET!
Another possibilty........A worn spot somewhere in your harness that only arcs when rpms are up causing vibration, and the suspension is working with your weight. Not a dead short but enough to draw more amps than your bike can produce. This would drop the DC voltage well below 12 volts and affect engine spark and your flasher. also check any plug connectors in your harness that may be losing voltage when they heat up and or vibrate.
When you get this figured out please let me know what the hell it is........Good Luck

 

Thanks, I am taking to my local shade tree mechanic for a little winter visit. I will let you know what it turns out to be. Are those LED's on your bike? How do you like them? I am thinking about getting some.