i have been tagging along on this thread, right now my mechanical regulator and stock rectfier on my 75 are working fine. if they fail i have the reg/rect out of the 82 seca donor bike. one thing i have thought about is if you have a reg/rect that is burnt out could you clean out the epoxy and internals and use the case to mount the r/s rectifiers in? that would give plenty of heat sink and a stock type mounting.
75 XS650B with 79 forks and dual disc, braided lines, disc brake on back, Pamco ignition, Pamcopete's reg/rec mods, kill switch relay, home made harness, all LED turn, brake and tail lights, tapered head bearings, bronze bushes in swing arm, soon to get shock and fork upgrades
Post by laotzuistruth on Dec 21, 2007 10:56:37 GMT -5
I just finished wiring up my rectifier last night. I was careful when soldering the unit, and soldered the wires right on the very tip of the bayonnets, and I feel pretty comfortable I didn't get the units too hot. To be safe I wish I put some hemostats on them each at a time, but we shall see.
Question. Is it really necessary to run a black wire all the way to the negative side of the battery? Please if someone can give me some info on this, I actually made my heat sink template the same size as the originial plate for the rectifier which is about 1.6 or so inches by approx 5 or 5 inches and i used heat sink paste under each rectifier chip, and will just run the negative underneath the mounting bolt to ground it.
P.S. The old rectifier only has four wires, three wires to the stator, and a power wire, as this adds a wire to the system, the ground That threw me off for a little bit.
thanks a lot for this information btw, this site is awesome.
The mounting stud under the battery box is not grounded. The battery box "floats" on it's rubber mountings, so you need to run the black wire from the rectifiers to a solid frame ground, such as the ground bolt for the negative battery cable.
Was there not a plug for the old rectifier? That is where the OEM rectifier it got it's ground from.
Also, the heat sink paste should be used sparingly. It is just used to fill in very small irregularities in the metal. Too much heat sink paste will actually be counterproductive and act as a thermal insulator.
Last Edit: Dec 21, 2007 11:36:24 GMT -5 by pamcopete
Post by laotzuistruth on Dec 21, 2007 11:35:17 GMT -5
Hmm, this was my setup. First, I have a 1977 XS650. The rectifier (I assume), is on the right side of the bike to the left of the battery box if you are looking at the bike. It is mounted diagonally, and has a clip mount for the plug on the side of its cover.
The power wire (I assume) is red with a white stripe. Then, the plug, is 3 wires, of varying colors, that I assume runs to the stator. The old mount is rubber insulated with the rubber pushed in the notch, and a steel spacer running in the middle of the rubber that the bolt goes through.
Well, I have a '78 and I don't think there is much difference in the two models. Your description sounds like the safety relay, especially the red/white wire. The rectifier is mounted on a stud underneath the battery box. It too should have a plug with three white wires, a red wire and a black wire. Take a look.
Last Edit: Dec 21, 2007 11:52:33 GMT -5 by pamcopete
Also, because you did not use hemostats to sink the heat from the soldering iron, check the resistance between each white wire on the rectifiers and the red and black wires, and then reverse the leads from your meter and do it again. You should read a low resistance in one direction, and a high resistance in the other. This will ensure that the diodes were not damaged.
Do this before you install the rectifiers because the circuitry in the bike wiring will influence your readings.
Last Edit: Dec 21, 2007 11:58:30 GMT -5 by pamcopete
Post by laotzuistruth on Dec 21, 2007 12:51:53 GMT -5
Will do. you saved me bike.
P.S. I just received my XS650 Shop manual in the mail! This will help identify parts heh.
Added at Midnight. I tested my rectifier and it passed the resistance test so apparently I didn't fry it by soldering it.
As a matter of fact, the regulator and Rectifier combo are working perfectly. I just put my rectifier where the old one went /shrug on a 1.6 by 5ish inch piece of aluminum with some heat sink compound. I did put some silicon sealer on the bare contacts to defend against shorts.
Just completed the rectifier replacement and am super pleased with the results. Previously I replaced the regulator with an electronic one as mentioned here and in another of Pamcopete's posts. Found the rectifiers at Radio Shack, the aluminum for the heat sink at True Value - just as mentioned on the post. Working carefully, I added a 20-amp fuse to the positive wire. Cleaned and re-used the OEM connector from the old rectifier, and used the stock bolt to mount the replacement. I used a metal spacer to allow a little extra room between the battery box and the heat sink, in hopes of keeping it cooler.
Took her out for a spin, and boy did she surprise me! Where working up to 70 MPH and beyond took a little pushing before, she was there before I realized it! She is one happy scoot now . . .
Thanks to pete my bike is charging. The rectfires from radio shack and voltage regulator from napa with orange wire brought back my 77 d motor back to life. I followed petes instuctions to the letter with exceptions no soldering all crimps cant soldering sitll I drilled cooling holes and used nylon spacers between the seat and rectifire heat sink where I mounted it now Im charging @ 14.2 constant volts thanx pete....
Last Edit: Oct 11, 2008 20:42:13 GMT -5 by jonbell
Completed the rectifier as detailed in the pics and the guidance by pamcopete- all very useful. pamco requested to post pics. I had to use green wire vice white wire since it came in the wire pack I bought. The ends connections to the new rectifier are relatively temporary until I get to soldering it. I installed it and it appeared to be working. I am working through lighting issues at the moment so haven't been able to take it down the road. I am still searching for the VR291/VR727 voltage regulator. I think I have a bead on it though at a local autozone. Thanks again for the details.
I used a camera phone so these aren't as clear as others.
r80rt: :)This is a splendid write up, THANK YOU!!!!
Dec 26, 2015 16:54:05 GMT -5
mashermoto: What the what is this shoutbox for? Or should I shout, WHAT THE WHAT IS THIS SHOUTBOX FOR!
May 12, 2016 22:22:21 GMT -5
motormike: Good Day ...just a FYI.. Wild Cat is this Labor Day weekend. Still go'n on. A few 650's still make the scene. Various rides at different skill levels each day.. awards dinner sunday eve. BS in the park'n lot after dinner.
Aug 23, 2016 7:57:01 GMT -5
lsettle: First post in over 6 years!
Aug 28, 2016 19:45:17 GMT -5
kardon: Wow quiet here, where did they all go.
Oct 7, 2016 2:18:13 GMT -5
gggGary: XS650.com LOL
Feb 16, 2017 20:49:02 GMT -5
buell88: Anybody have any idea who built the xs650 tracker used in the Draggin Jeans Ad on Pipeburn?
May 16, 2017 16:24:09 GMT -5
joshua: The regulator/rectifier unit I got from Mikes PMA has closer hole spacing than original. Are we supposed to mill the holes to fit?
Jun 7, 2017 19:25:58 GMT -5
joshua: My bad. I found the bracket they supplied to mount the rectifier/regulator... Uh oh. How is this meant to work? Which way is it meant to mount? Looks like I have to use some spacers or something. Good instructions would be nice.
Jun 7, 2017 22:09:52 GMT -5
craig8johnson: Not sure if this is the right spot or not but oh well...
Jul 11, 2017 18:04:15 GMT -5
craig8johnson: I'm checking the charging system. I'm afraid I might have fried the last battery. With the solid state regulator (after market) what should it be charging at. The book says, I think, 15 volts. I'm hitting 17 when revved. Is that too high?
Jul 11, 2017 18:06:19 GMT -5
gggGary: Yes 17 volts is too high, about 14 volts is max, sounds like you don't have the right regulator or it's wired wrong.
Jul 13, 2017 6:54:33 GMT -5
dean: Just saying Hello, new member who is going to fix up a 79 XS650 that has seen its better days. I will definitely have lots of questions coming up.
Jun 23, 2018 16:45:32 GMT -5
tt650: Trying to breathe life into a 1980 that's been stored (indoors) for 25 yrs. Air filters are dry rotted. Have cleaned carbs but she only runs briefly on choke then stops. Need jet setting info and other ideas that might help her idle and rev.
Jul 3, 2018 19:15:19 GMT -5
trix13: Hey everyone! New to the forum and am fighting those gremlins!! New charging system, ignition switch, coil and fuse box. Resistance is higher than normal on the ignition pick up so I'm trying to find one. No such luck yet.
Aug 16, 2018 8:50:48 GMT -5
trix13: Also, even though all of my connections are clean, I cannot seem to find out why , when at higher rpms, I hit the signals and the rpms pulse with the signals...hahah. same with the brake light. I appreciate all input!!
Aug 16, 2018 8:55:08 GMT -5
bob99: how do I post a question. I am new to the forum
Jun 6, 2019 10:52:10 GMT -5
adlpc: Hello all! Been enjoying your edifying posts and discussions - and as a fan of the XS650 since my early teenage years happy that I now own a 1980 Special which I plan to turn into a vintage half faired racer. Thank you all for being here!
Oct 1, 2019 0:58:56 GMT -5
jimothyj: Hello everyone, I just joined & wish would have known about this site in 2014 when I brought my 1974 TX650A back from the grave. I have spent a good deal of $$ and alot of time on it. Just painted it and working on electrical, I will post pics soon,
Apr 10, 2021 2:14:13 GMT -5
louisvan: trix13 - I had a problem with my 1975 SX650. When I got to highway speeds, the engine lost power. The problem was in the connectors. At a certain vibration and the wind pushing on the wiring loom, the connector lost continuity. A bad crimp to the wire.
May 20, 2021 1:19:09 GMT -5