Threading the needle of charging issues...

[Noodles]

Ok guys, here we go again! I know this is another thread that has been posted probably about a MILLION TIMES. So I am just going to say that I did READ THE MANUAL, performed the tests as they say. I did search around on different threads for answers, but it seems that they always start off with a straight forward question and ethier spiral off into nonsense, or after 3 replies dead end with nothing.
So here goes again: 1981 xs400sh thought that the batt. Was junk but turns out it's just not getting charge. Bike runs fine when running. But won't charge. At 1,000rpm. I got about 11.4v on batt. Rev up to 4,500rpm slowly increases and tops out at 12.7v...should be about 14-14.7v
So, chkd gen. Coils, (after rookie mistake of freaking out that there was oil behind gen cover!) coils all within range...on to rectifier, diodes all function properly(they have this test written funky in the manual, but with 2 yrs elec. Eng. Experience I would say I know how to test a diode!)..ok, so on to regulator...well...can't F'ING find a good true way to test the reg. Anywhere! How can you truly test if this thing is functioning properly? Any leads on a cheap replacement? You would think if the reg. Crapped out that voltage would spike and be all over the place not stay BELOW what it should be?? anyway, I hate electric systems on bikes, cars,boats it's always just a rats nest of wires, mystery issues, and redundant parts. Lemme tell ya, boats are the WORST! used to be an electronic tech., went to school for it...HATE IT, WENT BACK TO MELTING METAL (WELDER) anyway I digress...
I just want to get this thing charging for the summer and then rip out the entire wiring/elect. Sys. In the fall and update to all new, SIMPLIFIED system.. (m-unit, etc.)
Anyone got thier- to give?

 

[xschris]

The battery should start out at 12.5-.7 to start with. If all the other stuff checks out it should work.

 

[Noodles]

The battery should start out at 12.5-.7 to start with. If all the other stuff checks out it should work.

Not sure I get what your saying? What should work? I know for sure something is not working, battery will not charge. Only get 12.7v max at up to 5,000rpm...should read like 14.5 + - if charge sys. Is functioning properly. Positive that coils all read right, pretty damb sure rectifier is functional, that leaves the regulator, or loose wire/bad connection as the culprit. Is there a V-Reg. I could pick up from say oriley/vip that would work for under $50? V-269 or something like that I read on another thread. Seems to me a lot of people have this issue, and it seems to me that the v-reg. Is always in question. Never a definite answer though! Could be wrong I guess.

 

[xschris]

With the bike off the battery should say 12.5 to 12.7v that's a good battery. Always do the tests with a fully charged battery. If you have checked the alternator resistance values and they are all good ( page 109 in the manual) you should get a charge. If you still don't it may be the regulator. I have only used stock ones so I can't say what others work.

 

[Noodles]

Yeah, I went and bought a new battery, it runs great now and starts right up without dying out. So maybe it was the battery. My buddy swears it's just the battery. But I still only get 13v max. At 5,000rpm...manual says I should be seeing like 14-14.5v...
If the v-reg. Was toast, what would the symptoms be? Wouldn't the voltage be all over the place and jump up way higher than it should??

 

[xschris]

Usually it goes up but I guess it could stay low. Get another to see what happens.

 

[Ethanl]

my dohc bike was do to a bad new reg/rect everything checked out and was good in spec so I figured after hours and weeks of head scratching to by another reg/rect and just try it and it solved all my issues maybe a easy thing to do rather then go crazy trying to find a wire issue that maybe not there

 

[BBS360]

Looks like you'd be going for the V-125 regulator:
http://www.xs400.com/threads/aftermarket-regulator-wiring.7479/#post-78503

 

[arfstrom]

Did you ensure that the stator wires are fine? They tend to get 'shot' right at the bend from under the drive sprocket, to where it goes up to the first (last wire holder) (rear bottom of motor) before it goes up to the connector under the seat. typically it makes a crispy noise, like rice crispies. I had to do both, replace the wires, and the VR. I went with the BWD 296 from Oriellys, my local autoparts store.
http://www.xs400.com/threads/charging-sys.7707/page-4#post-88162
That post includes pics, checking for the price its going to $23.99 USD

 

[Noodles]

It's been raining like a bastahd out up here latley and I have been busy with work so I have not been thinking about the bike much. But I will be back on it today. New batt. Seemed to do the trick for now, but I will definitely update everything eventually. Is there any good threads I should look at for updating to a better ignition system? Get rid of that giant black plastic ignition box under the battery that's filled with atari and pinball machine parts marty? back to the future joke..stupid, I know!
THANKS FOR THE PART#'S AND THREAD LINKS.

 

[xschris]

That's the best ignition setup there is for these bikes (TCI). If it works just leave it. If it goes bad there are used ones that can be had for cheap also. You can get a pamco TCI setup for around $225 but it does the same as ours for the most part.

 

[BBS360]

Keep the stock TCI as long as it works.
When it does fail there's pamco Pete's replacement:
http://xs400ignition.com/index400E.htm

The newtronic ignition may work as well. I don't recall if it's for points or TCI bikes.