It finally stranded me.

ohms from green and brown wire these wires are connected to the brushes.
ohm the 3 white wires

The Ultimate Relay, Switch, Sensor, and Diodes Guide
from above link read it is at the end it has trouble shooting advice
Checking Alternator Stators:

Measure the resistance across each pair (white1 to white2, white1 to white3, and white2 to white3) of the three white wires (white1, white2, and white3) at the connector; the specifications should be:

0.50 ohms +/- 10% for all XJ550 models.

0.46 ohms +/- 10% for all XJ650, all XJ700, all XJ750, and XJ900RK models.

0.37 ohms +/- 10% for all XJ1100 models.

0.40 ohms +/- 10% for all XS1100 models.

Note that the resistance specifications for the stators are extremely small; they should barely have any resistance at all (compared to most other electrical devices).
Checking Alternator Rotors:

Measure the resistance across the two lead wires (usually brown and green) at the connector; the specifications should be:.

4.5 ohms +/- 10% for all XJ550 models.

4.0 ohms +/- 10% for all XJ650, all XJ700, all XJ750, XJ900RK, and XJ1100 models.

3.5 ohms +/- 10% for all XS1100 models (field coil).

 

Thanks. I'll try to check it out this weekend.

 

I may have found my problem. I removed the alternator cover and found oil inside and the inside of the windings were coated with oil and although the brushes looked ok I am sure they are coated with oil. A couple of years ago I tried to fix the oil leak that was, and still is, coming either from the oil nozzle and/or the alternator shaft flange. I replaced o-rings on both and had also found a pin hole size imperfection in the inside of the flange where the o-ring fit and tried to repair it by filling it with rtv. Could that be the source of the low voltage from the alternator? I have not checked all the connections, but the ones I have have been fine.

 

oil will cause drag and also act as an insulator on the brushes to rotor

 

It's a light coat, but it's everywhere. How would I go about cleaning the windings?

 

Electric motor cleaner.
Not contact cleaner or any other solvent.

As for the leak, and the previously discovered imperfection, I think it would be wise to shop for a replacement bearing carrier. The only other thing I would reccomend is fixing it with epoxy, but given how inconvenient it is to pull the alternator rotor you may as well as get a carrier that does not have that imperfection.

 

I happen to have a spare engine sitting on the garage floor and my plan was to swap the bearing carrier, but still try repairing the old one with epoxy. I will see if I can find some electric motor cleaner, and replace the brushes at the same time. Hope that fixes the problem--getting to be a pain.

 

The spare engine has no brushes but the shaft flange is good with no oil leaks so I want to exchange it with mine that does leak. I got two of the torq screws out using an impact driver but the third one won’t budge and has stripped the star points so that the torq driver pretty much just spins. Any suggestions on how to get it out short of drilling it? I don’t want to damage the flange or the engine.

 

Can you post a pic? That would help this brain give you some better ideas.

Will the next size of TORX or Allan bit grab if you tap it in?

I know you don't TIG weld, but you could epoxy a bit into the screwhead. Use the steel-filled epoxy and let it set up overnight.

If you do hae to drilll it out, use a left-twist drill and size it so you can drill the head off, leaving the stub of the screw. I would not use an extractor on it.

 

Had to drill the screw and use an easy-out extractor, but it came out. Got the flanges exchanged and the electrical parts cleaned and polished. Unfortunately, I broke one of the brushes getting the holder out to clean it. But I suspect they were saturated with oil anyway. Brushes on order from Chacal.

 

when you take those screws out, if they don't cooperate, drill the punch mark on the edge of the screw with about a 3/16 drill till you go through the screw and just a bit into the aluminum. they come right out, then use blue lock tite to put then back

 

Sounds like a good idea. I was a little worried about using the extractor, but I used he smallest one I had and fortunately it came out. I used lock tite (blue) last time and so I'm not sure I want to use it again, at least not until I am sure it no longer leaks. I just hope that after thoroughly cleaning all the electrical connections, polishing the rotor and the inside of the stator, and replacing the brushes I get full voltage and no leaks. If so, I think that will solve the cold idle problem.

 

do you use new screws and punch them? I guess this is a question for you and those who may know if it is required

 

I did not punch mine to lock them in place. Blue Locktite should not have made it that hard to remove the screws. Perhaps the heads were already damaged, or made of cheese.

 

I simply tightened them and gave the one good rap with the impact driver to tighten then a little more. If the oil leak stops then I will remove them and add a small amount of blue Locktite. The screws I have look good. The one that I had problems with was on the spare engine.

 

That's what I thought, but I was a bit confused afer all the responses.
Posting while packing up to move is a challenge.

 

Installed the new brushes and I now have 12.5 volts at idle, so that’s good. However, —there’s always a however it seems— when installing the brushes I discovered that one of the posts that the brushes slide in is broken and one side is missing. I guess I somehow broke that when removing the holder initially and did not realize it—just thought I broke the brush. So, when I try to rev it it boggs down. I assume that is because the brush is moving and messing with the timing or something. So, I am going to get a replacement and hope that solves the problem.,

 

I'm one of those goofs that put an inline autozone filter in and was stranded on the interstate for 45 min. Flow problem. Thought I ran out of gas. After a wait sufficient fuel returned to the carbs and I was able to drive to the gas station.

 

Primeline part number 7-02357 you can use the part number at any auto parts store to order them

https://www.xjbikes.com/forums/threads/how-to-install-a-fuel-filter.6352/#post-208637
https://www.xjbikes.com/forums/threads/inline-fuel-filter-longevity-alert.34020/

 

There are some rather nice (surprisingly) filters with sintered bronze elements and auminum housings avaialble from various sources on Ebay. I've been using one for about three years now. The advanage is that they do not have to be replaced each year like the filters with plastic housings.

Proper routing eliminates the risk of air pockets, and the filter eliminates the risk for additional downtime due to crud entering the carbs. The way XJ tanks are constructed it is nearly impossible to keep them entirely rust-free without using a liner. A filter is cheap insurance, but you have to use the right type.

 

i use the semi-transparent plastic jobs with the plastic mesh, probably the worst ones there are, but i want to see in there.
if i see a chunk in there i want to take care of why it's there before it's a bigger problem.
drain the float bowls every time you change the oil, just to be sure and keep the drain screws free

 

A few of my drain screws were stripped when I purchased the machine years ago. Still haven't drilled them out. Yet another drilling project to look forward to someday.

 

Soak float bowls with PB Blaster or Kroil , a impact driver will help as well or a propane torch heat bowl up. . After you get them out obtain new drain screws and put any sieze on the treads so this won't happen again.

 

when you get them out, put these back in

 

Switched out the black brush holder, installed the new brushes, cleaned everything with electrical cleaner and now I have between 12.3 and 12.4 volts at idle and it hits 14 volts at about 4000 rpm. So my electrical problem seems to be solved. Time will tell if the new alternator shaft flange will stop the oil leak I had with the old flange. In the process of doing all of this I also bought and installed the air box tube which was missing. It seems that it runs a little differently so I am wondering if that tube restricts air flow enough to require re-tuning and re-syncing.

 

I adjusted idle mixture and re-synched after installing the airbox tube. It was just a small tweak, but made enough of a difference to be worthwhile.

 

Figured I would do that this weekend. Thanks.

 

Rode it yesterday and it seemed to run fine until I made a hard leaning left hand turn and it dropped a cylinder. But corrected itself in about 150-200 feet after straightening up and ran well for the rest of the way home—about 1/2 mile. Added some sea foam this morning and went to top off the tank and after about a mile it dropped a cylinder again and it never came back. Got home and #3 exhaust is cold. Pulled the plug and it has a very good spark, so I am hoping that my fuel problem is just a sticking float and the sea foam will loosen it up, or it’s back into the carbs. It was running great before my electrical problem and I am surprised that a carb problem would pop up after sitting fo a little less than a month.

 

sounds like float level to me. did you wet set the carbs level on the bench?

 

Float levels were set when I completely went through the carbs about 3 years ago. Included new seats and brass needles. I am hoping it just got a little sticky while sitting for a month, and that is why I am trying the Sea Foam.

 

Time to pull the carbs, Sea Foam didn’t help. Bike stars, idles and runs well for about 1/2 mile then I guess the #3 carb empties because I lose that cylinder. I wonder why these carbs seem to need so much attention. I have a 2001 Honda Shadow, a 2004 Honda Aero, and a 2004 Honda Rebel and have never had to touch the carbs.

 

I never cared for the spring pin needles. It should be on or off without any play in the lever setup.

 

He has solid brass float needles. No springs.

 

I haven't messed with mine in 7 years. I did mess with a spare set a few years ago, and haven't touched them since setting them up.

There could be something going on that you missed earlier. Maybe a burr on a float pillar.

 

We will know as soon as I get in there—probably Tuesday night. Wife will be gone all week, so I have plenty of time.

 

Garage time! At least as long as it's not 150F heat index like it has been here. I need a 2T mini-split in my garage.

 

Carbs are off, apart and soaking in cleaner. They all were pretty clean, but as I suspected there was some gum around the seat, needle and screen in the number three carb. Have no idea why only that car would have gum but it did. What is your opinion about the screens attached to the needle seat? Originally there were none but I added them when I replaced the original seats and needles. Now that I have a good inline fuel filter I am considering leaving out the screens.

 

if you have carbs apart you could pull them off as long as you are using a filter . screen would hold back a chunk of fuel line after the filter keeping it out of your needle

 

Thanks, my thoughts also. My filter is just a coup of inches above the fuel rail.

 

Carbs are clean and back together, The more I think about it, I think the real problem I had with the #3 carb was that the screen over the needle valve was clogged and not allowing enough flow to keep the bowl full. The needle and seat looked fine and the needle was loose, although there was a little gum on the seat. In any case, it's all clean and I omitted the screens since I am running a good inline filter. Since I didn't change anything with the needles or floats I was tempted to just re-install the carbs without checking the fuel levels or check for leaks. But having made that mistake before, I put that temptation aside along with the carbs and will do it tonight and then reinstall the carbs. Sometimes I'm not long on patience. It has been several years and I had forgotten what a pita it is to pull and install the carbs.

 

Success! At least I hope so. Had more trouble than I remember getting the air boots back on, but everything is back on and it starts and runs well. At 74, going on 75, I sure hope this is the last time I have to deal with the carbs. When I first tried to wet set the floats I had a problem with one of the needles and gas was pouring out of the overflow line. Figuring it was the same carb that was the original problem I pulled that bowl and blew it out. Still leaked, so I pulled all bowls and blew out the gas line and blew air through the needle seats. Put the floats and needles back in and hooked up the gas with the carbs inverted and no bowls to see if any were leaking. Lifted the float on each carb to be sure fuel flowed and stopped when the float was resting on the needle. Installed the bowls and let it sit for an hour just to be sure there were no leaks. First time I had ever used the inverted carb method to check the needles, but it worked for me.

 

It has always run well, or at least I thought it ran well. In the past I have to admit to being a little concerned about it occasionally shutting down at idle. However, after replacing the alternator brushes and getting a full 12.5 volts at idle, it starts easier, idles a lot better and runs amazing well. Removing the screens on the needle seats and cleaning the jets and fuel rail solved the cold cylinder issue. If XJ550H had not mentioned checking the voltage I would have never considered that it had low voltage or that that would cause a problem with idle. Live and learn. Thanks.

 

Just a follow-up note. Believe it or not, since I installed the new alternator brushes my fuel mileage has gone up drastically. Today I filled up and added 1.52 gal for 75.6 miles, or about 49 mpg. Even if I was off by 1/10 gal that still is over 46 mpg. I have been noticing that the mpg seemed to have increased so i wanted to wait until I had checked it several times. The only possible explanation I have is that the new brushes and higher voltage from the alternator somehow has resulted on a hotter spark and more efficient burning of the fuel. Am I completely nuts?

 

less. drag on alternator to charge battery and run lights is also a reason for better gas milage