No Charge or #3.

[conquest87tsi]

So I got the exhuast on today and everything buttoned up and decided to start the bike up and see where I was. It popped off right away and was apparant it was only running on two cylinders. Felt the exhuast and sure enough 1 and 4 were cold. I removed the coil and checked resistance. It checked out fine. I plugged in a spare ignition unit and it fired up right away. I then noticed that the headlight was off, tach didn't work, nor did the speedo or tach lights.

I tested the resistance at the alternator plugs and they were fine. I replaced the rectifier with a spare, but need to wait for the battery to charge to check it out.

After checking the Alt and Rect I started it again and it wasn't running right. Now all but cylinder 3 fire. There is intermittent visable spark from the wire (only saw once). And fuel on the plug. Why would I just lose cylinder 3? Could this just be a symptom of running on my battery? Any ideas on the charging system? Where to look? I did hear something loose in the old ignition unit when shook. Odd, I ran it with that unit prior to restoration.

[bikerphil]

A test to see if the bike will charge is to tap into the green field coil wire (2 wire plug by the fuse panel) and connect the tap to ground, this will give full voltage (safe for testing purposes) from the alternator to confirm it is working.

As for #3 not firing, you can unscrew the spark plug cap and trim 1/4" off the wire and reconnect, might have corrosion prohibiting good spark, JAT.

[conquest87tsi]

Good tip on the green wire, I will give it a try. As for the plug wires, I have freshed up where the cap screws in and rechecked on affected cylinder. I did confirm that the ignition unit is junk.

I replaced the right coil with a known good coil. Still nothing from #3(cold exhuast and fuel on plug). I then rechecked compression. 120 across the board. I then switched the #2 and #3 plug wires. Same thing.

It was very apparent that it wasn't firing as I have freshly painted exhuast and the other 3 pipes discolored quickly and uniformly. After running a while I thought it had come out of it as the pipe got really hot, almost as hot as the others.( Not from convection) Also, it seemed to be running well, with very little smoke from exhuast. However when I removed the plugs, #3 was the only one wet with fuel.

I guess the only thing I can think of is that #3 is running too rich. May put my spare carbs on tomarro to verify.

[conquest87tsi]

Phil,
are you talking the green wire that is routed with the starter?

[CaptonZap]

Phil,
are you talking the green wire that is routed with the starter?

I think he is talking about the green wire that comes out of the alternator cover, on the right side of the engine case. It goes to the voltage regulator. You can take a safety pin and run it through the green wire, and take a jumper wire and short it to ground, or take the wire out of the connecter and do it that way. That allows full output from the alternator. When you do that, you should see an increase in voltage to the battery.
The green wire on the starter terminal is the ballast resister bypass feed.

CZ

[bikerphil]

No, find the 2 wire harness going down to the alternator with a green and a brown wire, do not disconnect anything, just tap into the green somehow and ground it.

Zap you got it.

[conquest87tsi]

Ok,
I checked the resistance values on both the original and replacement rectifiers. On the original I wasn't able to get continuity under any condition. So obviously it was junk. On the replacement I got around 530ohms on all I was supposed to.

I then rechecked the stator. I again got. 5 ish ohms between all white wires, BUT when I checked continuity to ground I got continuity on all three! I read in another thread that this shows that the stator is junk. Is this correct? It makes sense. The resistance to ground was almost the same as resistance to the other white wires (.5ohms).

The stator currently installed came from a parts bike and was never verified. I wanted the cover painted so painted that one and just removed the original and installed it. So I have the original. Could the bad rectifier have fried the original alternator? Could I have two that are junk? I could test with the one from my SF, but don't want to fry it to. Actually have not checked it's funtion, just has always kept the battery charged.

[bikerphil]

Could the bad rectifier have fried the original alternator? Could I have two that are junk? I could test with the one from my SF, but don't want to fry it to.

I'm not 100% positive, but I doubt a bad reg/rec would fry alternator windings, I have never heard of that happening on an XS11, and yes it is entirely possible to have 2 bad alternators. The alternators very rarely go bad on these bikes but if the stator has been removed from the casing, that's another story. I'd throw on the extra one you have and try that if the testing #'s check out, if not, Ebay probably has plenty of them or member Andreas.

[skids]

I'm not 100% positive, but I doubt a bad reg/rec would fry alternator windings, I have never heard of that happening on an XS11, and yes it is entirely possible to have 2 bad alternators.

I would agree with that. The stator field coil wiring should be separate three phase circuits I think. I think you can fry a field coil. No magnetic field, no charging.

I am not sure what causes that, but I had to replace one once. It would not hurt anyting to run the bike by jumpering it to a car battery with that engine off. This might help you figure out if your firing problems are related to the charging system.

It was a bit strange that your problems moved from 1 and 4 to the 3 cylinder. Maybe I missed something there.

Make sure that there is metal contact between the VR and the frame as this is how the VR is grounded. Make sure that the connections for the stator clip located behind the fuse panel are good. There is a lot of voltage (20+ volts) that can be generated and this will cause arcing and heat if the contacts were/are bad. Mine were fried when I noticed that my field coil was fried, although I can for sure say that was the reason.

[conquest87tsi]

Thanks for the words of wisdom guys.

As for the problem jumping from 1 & 4 to 3, the ignition unit was bad which cuased 1&4 to not fire. I think #3 was firing just enough to warm the pipe a bit. Now that I have 1&4 running, it is apparent #3 isnt right. I am almost positive that something isnt right in the carb. Its getting fuel, but isnt running right on that cylinder. So one of the carb circuits is screwy. Ganna through on my '81battery spare carbs and see what happens. At least then I know I need to clean the other carbs again.

Will have more details on the charging issue in a couple hours I suppose. I did reove the coils to paint the cover. Unfortunitly I will probably do it again to put the donar coils in the painted cover.

[skids]

Mine were fried when I noticed that my field coil was fried, although I can for sure say that was the reason.

That should have read "can't"

[conquest87tsi]

Well, I took the alternator off today and noticed that the yellow and two white wires had been pinched and the insulatiin was cut. I cut, soldered, and shrinked the wires. Spun the coil 45 degrees so the same spot wouldn't be bent again. I then taped some of the removed insulation over the spot that would exit the cover, removed the rubber "grommet" on the wires and just filled the whole void around the wires in silicone. Once it dries Ill install and see whats up.