Tombo
XS400 Addict
Hey everyone
First - sorry, this is long.
I have 1980 xs400 special ii that I picked up about a week ago. I had got it to run decently, but then noted that I was having a charging issue (not charging, very low increase in voltage when at 2-3k+rpms)
I followed the manual through the various steps:
1) Checked alternator - the two green wires (one really looks black to me, both are fiber wrap) read at 4.6 ohms
2) Checked the 3 white wires - 1.1 ohms across each.
Lets stop right here - are these readings "bad"? They are a bit out of the given spec - but I went ahead and checked the rectifier, which read within spec.
Having no conclusions from my diagnostics, I decided to go ahead and change the voltage regulator, as had been described as a successful "fix" and a potential "upgrade". I figured if it changed nothing, at least I would have a more solid regulator BEFORE it failed. In retrospect, it seems like it caused more problems.... But perhaps I did something wrong.
Heres what I did:
Located the regulator, cut the black, green, and brown wire off of it, then grafted on a bullet connectors to attach to my new R296 unit from O'reilly. The green wire is attach to the upper left, the brown to the lower middle (there are only two) I put a ring connector on the remaining black wire from the stock harness (noting in wiring diagram that it ran to the negative battery terminal), and grounded it to the body of the new R296.
Now the bike runs like total shit. Difficulty starting, then once it's started it backfires into the left side air box intermittently. And Alas - NO charge! None (I had a LITTLE before this).
So I tried one more time to ground the body of the new unit by adding a new ring to ring piece of short wire, and grounded it with the other black ground ring to the left of the battery box and to the body of the unit. No change.
What I'm confused about, is how the bike seems to run so much worse now that I've made the change. Perhaps I did something wrong!?
I'm out of ideas short of diving into the stator and alternator. Your help, please!
First - sorry, this is long.
I have 1980 xs400 special ii that I picked up about a week ago. I had got it to run decently, but then noted that I was having a charging issue (not charging, very low increase in voltage when at 2-3k+rpms)
I followed the manual through the various steps:
1) Checked alternator - the two green wires (one really looks black to me, both are fiber wrap) read at 4.6 ohms
2) Checked the 3 white wires - 1.1 ohms across each.
Lets stop right here - are these readings "bad"? They are a bit out of the given spec - but I went ahead and checked the rectifier, which read within spec.
Having no conclusions from my diagnostics, I decided to go ahead and change the voltage regulator, as had been described as a successful "fix" and a potential "upgrade". I figured if it changed nothing, at least I would have a more solid regulator BEFORE it failed. In retrospect, it seems like it caused more problems.... But perhaps I did something wrong.
Heres what I did:
Located the regulator, cut the black, green, and brown wire off of it, then grafted on a bullet connectors to attach to my new R296 unit from O'reilly. The green wire is attach to the upper left, the brown to the lower middle (there are only two) I put a ring connector on the remaining black wire from the stock harness (noting in wiring diagram that it ran to the negative battery terminal), and grounded it to the body of the new R296.
Now the bike runs like total shit. Difficulty starting, then once it's started it backfires into the left side air box intermittently. And Alas - NO charge! None (I had a LITTLE before this).
So I tried one more time to ground the body of the new unit by adding a new ring to ring piece of short wire, and grounded it with the other black ground ring to the left of the battery box and to the body of the unit. No change.
What I'm confused about, is how the bike seems to run so much worse now that I've made the change. Perhaps I did something wrong!?
I'm out of ideas short of diving into the stator and alternator. Your help, please!