82 XJ650 Cafe Build

I've still got the carbs off for some percussive maintenance but other than that everything else is falling into place

 

I know that carbs can get on your nerves, but beating on them won't do any good.

 

Ok so I've purposely not been posting anything about problems with my carbs to avoid the pod filter debate but I'm stumped so here it goes.... Pod filters and 4-1 open exhaust is my setup. Currently at 116 main jets and 40 pilots, mixture screws at 2 1/4 turns out. It'll start up and idle good, occasionally the idle will hang when you rev it up some. I took it out on the road for the first time yesterday and when I first started out in first gear it's acting like its starving for gas, no power. After a few minutes it cleared up and ran great, it actually surprised me how fast it was. I got stopped at a red light and the idle hung way up around 4k and then acted like it had before with no power. Any ideas? I'm stumped, I pulled my plugs and they were all black, that was after tinkering with it some at idle trying to get it going again. It seems to have symptoms of rich and lean mixture?

 

hanging idle can be caused by the carbs being out of sync. you really should get a color tune to help set the idle mixture too.

FU

 

Happy Friday the 13th y'all

 

oh! no! pm me I have a couple extras laying around.

FU

 

Ever get that carb replaced?

 

I did, I bought a new old rack from a salvage yard that are super clean on the inside. Between studying for my NREMT test and moving though I haven't worked on the bike in a while. Hoping to put the new rack on next week and see what happens.

 

I put about 30 miles on it today! It's been a long two years but I'm stoked on how it's come together. Big shout out to Len for all the parts and all the advice on carbs! After chasing demons with rejetting it turned out that once I got the fuel levels wet set in spec, removed the shims from the needles, and got a good vacuum sync on the carbs that I ended up being dead on with the jets that were originally in the carbs when I got the bike lol. Once I'm 100% happy with how it's running I will post the specs as a "pod filter success story." Other than that I still have some small detail work to do, I plan on taking lots of photos of the finished product once it gets there!

 

I've been having too much fun riding around town to get more pictures! I've got some little details to tweak but it's there! She's a screamer

 

Hey guys question.... I've got a problem in my charging system somewhere. My buddy tested the stator and it tested ok. I tested my regulator box yesterday according to the Electrical FAQ write up. My red wire coming from regulator had good high voltage but the green wire was reading .54v at idle and didn't budge when I rev the motor. The spec according to the write up for the green wire is 1.8v at idle and 10-11v when revved. Could this most likely be my problem and is there a way to test before buying a new regulator?

 

Process of elimination. Test the entire charging system. If everything else test good that's the problem. Hope this helps.

Gary H.

 

If the stator output is OK, but the regulator output is not OK, then you have found your problem.

 

Also double check ground wires

 

The low voltage on the green wire is an indication that the regulator has sensed a low output and is trying to increase the output voltage by increasing the current (excitation) through the rotor. However, if the brushes, rotor or wiring are causing an open circuit, then no excitation and consequently no output. In a working system, the green wire voltage increases as the speed of the engine increases to reduce the excitation and consequently the voltage output.

A somewhat simple test on the brushes / rotor to check for excitation and no open circuit:
Turn the key on while holding a thin feeler gauge about 1/2 inch from the AC Generator cover. If the circuit is complete and current is flowing through the rotor a magnetic field will occur pulling the feeler gauge toward the rotor cover.

How did your buddy check the stator? Did he actually measure the voltage output or did he just do the continuity check?

 

You are an amazing person............

 

Yeah he measured voltage on each white wire coming from stator before they plug into the harness

 

Well, that would be a good indication of the AC Generator and the IC Regulator performing as they should. The next part of the process would be the rectifier portion of the Reg/Rect Assembly. If the stator output voltages are correct, then the rectifier should turn the AC Generator output into a DC voltage to charge the battery... the 14.5V +/-.3V.

The shop manual has a good test for checking the diodes in the Reg/Rect. The only part it leaves out is to do it as a stand alone unit, otherwise you may get some false readings. Also, much easier with an analog meter if you have one, but a regular DMM will work if it has the diode setting.

Also re-read some of the post, and it appears you were having wiring issues early on. It would be prudent to verify the output of the regulator is wired correctly - the red and black wires. Perhaps during your wiring process the rectifier output was not connected as it should be, which is equivalent to running it with the battery disconnected. The result of that is an overvoltage condition from no load and that will damage the rectifiers in the Reg/Rect Assembly as noted in the FSM.

 

I'm definitely weak on doing the electrical system but I'm learning more and more as I go along. The regulator is definitely hooked up correctly though, the original connections had done corrosion problems so the plug was taken out of play and each wire had new connectors soldered on and heat shrank. The multimeter I have access to does not have the diode setting on it so I wasn't sure how to test that portion of the regulator box. The only portion I was able to test was the voltage on the red and green wires. I have also gone back over all my grounds and tested resistance and they all checked out, even ran some extra grounds and didn't change anything. Originally thought that was the problem.
The only other wiring problem I ever had was a short in the connection for the headlight "tail" but that caused a complete power loss to the whole bike until it was corrected.
I appreciate the advice and direction, I thought the carbs were tedious until I dove off into wiring!

 

I missed this yesterday thinking you were measuring input power to the Rect/Reg since you were referring to testing per the FSM. However, that would be a Brown wire, and the Red wire would be the output of the regulator. So now I am wondering if it was the red wire what kind of voltage were you reading, or were you really checking voltage at the brown wire?

 

I was going off this spec sheet, I tested voltage on the red wire coming from Rect/Reg and I don't remember exact number but around 20-25v, increased if motor was revved. I then tested voltage on green wire coming from Rect/Reg and got .54v and no change if motor revved. When I tested each of these the other wires were still plugged into Rect/Reg (3 white wires, brown wire, black wire)

 

The joys of trying to troubleshoot over the internet, my apologies for misinterpreting your issue:

If the red wire (Rect/Reg) is truly 20-25 volts, this would also be the battery voltage if this is what you measured with everything hooked up and wired correctly. That much voltage would at a minimum blow all the bulbs, severely overcharge the battery, and likely damage the TCI. Since you have been riding the bike and haven't had a catastrophic failure I am suspecting some communication issues here.

So, back to the wiring. If the Rect/Reg is not connected correctly with the battery acting as a load, it will overvoltage per the FSM. Do a continuity check to verify that the red wire from the Rect/Reg connects to the battery positive, and the black wire from the Rect/Reg connects to the battery negative. Disconnect the battery when making these checks, and ohm directly to the large cables that connect to the battery.

Did you measure the voltage across the battery earlier when you were testing?

 

Here is a link to a very nice minimum wiring diagram provided by Polock. Not sure how much wiring you changed, but this depicts the wiring on the Rect/Reg very well.

http://www.xjbikes.com/forums/threads/its-another-spark-issue.59205/#post-450056

 

Yes I checked voltage at battery and the highest I've gotten to is a little over 13v at about 5k. I'll try the continuity test to make sure the wires aren't backwards but as far as wiring on the bike goes I really didn't "hack" it up so to speak, I just relocated the harness underneath my seat but didn't change anything about it. Also I don't think I mentioned, the voltage at the battery drops when my headlight is on, I know it's a big draw but didn't know if that was any indication.... Only get 12.4-12.6v at 5k on the battery with headlight on

 

And no worries on that! I appreciate the help! I'd ride on over to Jacksonville and let you take a look at it but my battery would probably die before I got there haha

 

I'm on shift today but I plan on going to the shop tomorrow when I get off, I'm going to check the continuity from the reg/rect to the ends of the battery cables and also the brush/rotor test. Do you have the motor running for that or just the battery and kill switch on?

 

After seeing what your running battery voltage is it would appear everything is wired correctly.

So going back to what K-moe had already stated, if the voltage out of the stator is OK, then the Rect/Reg must be bad. Since you don't have a meter to check the diodes, it is possible that you are just missing one leg of the diode bridge, which would lower the output voltage.

To check the magnetic field with a feeler gauge everything hooked up and turn the key on. The ignition switch output supplies power for the excitation power so you don't need the kill switch on.

Edit: corrected power statement for excitation.

 

Many thanks! I'll test the magnetic field tomorrow as well as retest my voltage coming from the Rect/Reg on the red and green wires and let you know what I find out.

 

Yep tested my voltage again, 23v off red wire and .54v off my green wire. Unsure about diodes in Rect/reg

 

I just moved the alternator cover and one of my brushes is a good bit shorter than the other as well

 

Also forgot to add in my original post, the original fuses were replaced with a two 30 amp circuit breakers. I found a bad connection where my green and brown wires from brushes plug into the harness. I redid those connections and nothing changes. 23v on red and .54v on green coming from Rect/reg. I did notice if I unplug the green wire while testing the red it drops down to 11.85v at idle. While I was examining brushes I tested resistance from wire end to brush end and that was all good and all those connections were clean. And it did pass the magnetic test as well as continuity to battery cables.

 

First: switch back to fuses, or at least change one of the 30A breakers for a 10A breaker on everything but the main circuit. You cannot, and should not be tying in the lower amperage circuits into a single safety device. By doing that you are asking for an electrical fire.

As for the alternator brushes: So long as they are within the wear limits they will be fine. One brush will wear faster than the other due to the nature of the brush arrangment being at different radiuses of the alternator rotor.

 

I will double check this later this evening, but curious on your hookup. So the red meter lead is on the red wire from the regulator, where are you connecting the black meter lead?

This would disable the AC Generator as it would remove excitation, so now you read just battery voltage. Trying to imagine how some wiring error or hookup has effectively placed the generator and battery in series to get 23V??

+1 on what K-moe said about the fuses. Don't want to have 30 amp breakers on circuits designed for a maximum of 10 amps. I am guessing you have one 30 amp for the main and the other 30 amp combined for the Ignition, Signal, and Headlight?

 

When testing I placed red lead on the red wire tail coming from regulator and the other to a ground point on my frame. I tried a couple of different ground points even the regulator box itself and got the same reading each time. I can't imagine what could be causing that much voltage other than my regulator being bad?

 

I thought for sure I had found the culprit when I discovered how corroded this connection was where the green and brown wires from brushes plug into the harness. I redid these connections however and nothing changed.

 

OK, did a sanity check just to be sure. The Rect/Reg red wire should be the same as battery voltage (14.5VDC +/- .3 at 2K RPM and above) in respect to battery negative or chassis ground. So, still confused as to why you would measure 23VDC on the Rect/Reg red wire. If the Rect/Reg red wire truly connects to the battery positive, and the Rect/Reg black wire connects to the battery negative, then they are electrically the same. With that, the voltage at the battery would have to measure the same as the voltage at the Rect/Reg. In other words, if you measure 23V at the Rect/Reg red wire, then you would measure 23V at the battery if the system is wired per print.

Just to throw some other things out there to check since you did move some wiring and I'm not sure of the extent of the change:

The motor and the frame should be at the same potential. On some of the XJ's this is accomplished through the motor mounts. On others, there is a separate ground wire that ties the motor to the frame. Powder coating engine mounts or the frame could cause an issue if a secondary ground wire is not used. On the 650 there is normally a separate ground wire that connects the engine to the frame. Battery negative connects to the engine and then the separate ground wire connects the engine to the frame. The engine harness ground bus ties to the frame, typically this is one or two eyelet terminals that are grounded to the frame via the ignition coil mounting hardware.

Get the fuses wired per the original diagram. The Rect/Reg positive output normally connects to the battery through the main fuse. I can't imagine a configuration here that would cause your issue, but to prevent an electrical fire down the road the fuses / circuit breakers need to be sized for each individual circuit to provide the proper protection.

Beg, borrow, or buy a DMM with the ability to check the diodes in the Rect/Reg. Harbor Freight has some cheap one's that will do the job. Without finding a defect somewhere, then the only alternative is just to replace parts to attempt a fix. If you don't know what the defect is, then sometimes there is the potential to damage new parts.

 

Let me throw this out there so I can make sure we're on the same page, when testing that red wire I have been unplugging it from the harness and using the end on the regulator side to test, getting the 23v. Is that the way it should be tested?
I've triple checked all my grounds and made sure they were touching bare metal (powder coat removed). Motor to frame, wiring harness has two points to frame, and battery to frame, and rect/reg is grounded to frame.

 

No, that explains a lot thankfully. In fact, doing it that way can actually damage the rectifiers in the Rect/Reg assembly as it is equivalent to running the bike with the battery disconnected creating a no load condition for the Rect/Reg.

So, to me the next step would be to ohm out the diodes in the Rect/Reg as I like to attempt to isolate why something is failing. When checking the diodes, it is best to do this with the Rect/Reg disconnected from the main harness. If you don't want to go there, then time to buy another Rect/Reg and give it a try.

Unless, you were disconnecting the green wire to check it also. The way the Rect/Reg works is through sensing the voltage output. The green wire acts as the control line to regulate the voltage so everything must be connected to evaluate the system. At max output of the AC Generator, the green wire is less than 1.8V as specified in the FSM - I get like 1V at the green wire with the bike not running. The lower this voltage, the more current that is supplied to the field coil as excitation. As the engine revs, less current is needed in the field coil to get the desired output, therefore as the Rect/Reg senses this rise in voltage, it regulates the output by raising the voltage on the green wire to reduce the current through the field coil to regulate the output.

Doing the magnetic test it just a quick and simple test to check for opens. It does not conclusively verify the condition of the control lines, brushes, and field coil. For example, it is possible that marginal brushes, field coil, or regulator will produce a magnetic field, however it could still be insufficient to get the job done. That is why the FSM has a detailed test for verifying the condition of the brushes, field coil, wiring and regulator by testing the voltage on the green wire. If this test fails the recommended action is to replace the Rect/Reg, as it also assumes this was proceeded with the continuity checks to verify the condition of the brushes / field coil and stator.

 

When testing it I only disconnected the red wire, although I did test one time with the green wire unplugged as well and that's when it dropped down to 11.8v on the red wire. When I tested the green wire I only unplugged it and got .54v on the regulator side with the bike running.
So the proper way to test the red wire would be to leave it plugged in and place the test lead on the connection? Same with green?

 

Correct on both, however with everything hooked up (should be) testing across the battery can take the place of testing the red wire at the regulator.

 

Dang, just when I thought I was getting the hang of it haha. I'll run a test on the diodes and voltage with everything hooked up and see what I get.
When I did the magnetic test I was only getting a magnetic field when the bike is running, if the key is just turned on it didn't have a magnetic field.

 

Also, when I do retest those two connections the correct way, if I were to see 14.5v on the red connection would that mean there's a bad connection somewhere between there and the battery? I'm on shift today so I won't be able to do any tests until tomorrow at the earliest.

 

Well you should. This is indirectly one of the test in the FSM:

-----Turn the main switch on, make sure V2 (green wire) is less than 1.8V.

There is a bit of a flaw in the FSM statement, but as stated earlier it is assuming the continuity testing was previously done on the field coil and stator. The flaw is a voltage of zero, which would indicate and open circuit in the field coil, brushes to slip ring, or wiring. So, with the main switch on, if all is well current should flow through the field coil producing a magnetic field.

I suspect you will see the same between the two points, but yes it would be possible for a poor connection to lower the voltage if they were different.

 

Did some more digging around on here: http://web.archive.org/web/20071214...ities.com/MotorCity/Speedway/7795/chgman.html
It's saying that the green wire should be putting out 14.5v and the brown should be 1.8 increasing with RPM's so have I been testing the wrong wires for wrong voltage as well? I don't have a service manual on hand.

 

That link is a copy of the FSM I am referencing. V1 and V2 are incorrectly labeled on the link as well as in the FSM. The brown wire connects to the output of the ignition switch, and is the input to the Ignition, Headlight, and Signal fuse as well as the Rect/Reg. Therefore, it will be battery voltage. The red and brown wire are electrically the same once the key is switched to on so checking the 14.5VDC +/- .3 volts can be done at either of those points, as well as at the battery. The manual specified the brown wire most likely as it is input power to the IC regulator and power to the field coil.

 

Ok so I tested my rectifier diodes and they are all fine. I tested the brown against green at its connection point into harness and got 47 ohms vs the manual states 4.0 ohms. I had a bad terminal there but I tested on the bare wires for that reading. Does this mean I have a bad field coil? Those wires go directly into the alternator cover and the connections in there were clean so is there another point I could have a weak connection?

 

I would pull off the gen cover and put the probes directly on the rotor's copper commutator strips ("rings"----and they are shiny clean, right?) and measure the resistance there. If it's still out of spec there, then the rotor is toast. If it's okay there, then move back up the line and determine whether it's bad brushes (sorry, don't have any specs for those besides length) and then back at the green/brown wire terminal block (unplugged from the main harness, of course). When testing at the connector, test from the front side, back-side, etc.......see if the reading changes. There can be corrosion INSIDE the wire bundles, hidden by the insulation, for a half-inch or so. If so, you'll need to snip off the wires, get new end terminals, and crimp/install them into the old connector shell.

 

Ok Len thanks, I'll give that a shot! Should I get the same reading when testing the rotor, 4 ohms? I can tell you when I pulled the cover off the other day the rotor was nice and clean, I wiped it down good and also scrubbed the ends of the brushes, the green and brown wire connections there were good and clean. Where the green and brown wire terminal block is had very corroded connections so I cut the wiring back like you said and soldered new connections.

 

My harness itself worries me a little, it seems to have corrosion throughout it, even in the middle of wiring where I've stripped back to test. Part of me wonders if I'm just chasing my tail!