TOPIC:

loudhvx wrote: Since you already replaced the reg/rec, and the stator, the last thing left is rotor, (and there is always a possibility of a wiring issue too). So you can maybe cut to the chase and replace the rotor. But since you already went through the frustrating experience of replacing parts and not getting satisfactory results I thought I'd mention the more involved tests.

Sorry it's not resolved yet.

No need to apologize.

At this point I am not sure where to go next. I guess your load circuit will give me more information about the stator and rotor. The only problem is I have no way to measure rotor magnet strength. A new rotor is out of the question (list price is almost what I paid for the bike) and since there is no performance spec I have no idea if a used one is any good.

swest wrote: Is the rotor permanent magnet type?
Steve

Yes it is.

I should also mention, I don't recall having ever seen a confirmed case of a Kz550 rotor being weak, where a new/used one definitely cured the problem. There have been a few threads where 550's had weak systems where everything but the rotor was replaced, then there was no conclusion after that, so it's not impossible.

You mentioned the bike was in an accident, which is why it was out of service for awhile, is that correct? If so, was there any damage to the left side engine cover? One of my motors had left side damage and the rotor was no longer true. That made some of the magnets have a greater distance to the stator. I never ran it like that, though.

If the alternator is putting out the correct AC voltage, doesn't that pretty much eliminate the stator & rotor as the source of the problem? I would focus on the used voltage regulator that was installed. And make darn sure the battery is good by testing --- new doesn't necessarily mean good.

loudhvx wrote: I should also mention, I don't recall having ever seen a confirmed case of a Kz550 rotor being weak, where a new/used one definitely cured the problem. There have been a few threads where 550's had weak systems where everything but the rotor was replaced, then there was no conclusion after that, so it's not impossible.

You mentioned the bike was in an accident, which is why it was out of service for awhile, is that correct? If so, was there any damage to the left side engine cover? One of my motors had left side damage and the rotor was no longer true. That made some of the magnets have a greater distance to the stator. I never ran it like that, though.

The bike slid on the right side. The left side of the bike is as pristine as a 30 year old bike can be.

martin_csr wrote: If the alternator is putting out the correct AC voltage, doesn't that pretty much eliminate the stator & rotor as the source of the problem?

That is what I thought as well which is why I did not first replace the stator.

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationThe problem is that the manual's stator tests are unloaded. That means little to no current is flowing during that test. When there is little to no current, any resistance in the stator wires will produce little to no voltage drop during the test, so the output voltage will pass the test. But when there is a load, the current will be greater (than when there was near 0 current), thus the resistance will heat up and get higher in resistance as it does so, then the output current will slowly drop, thus the output voltage will steadily decline with time.

Since the stator was replaced, I suggested the rotor, but like I said, it seems unlikely based on over 20 years of working on 550's and reading threads on this forum for 15 years. That does not mean impossible, obviously.

To rule out the reg/rec, you could buy try a brand new, 3-phase rectifier. They go for less than $5 on ebay (from China). It won't regulate, thus full power will always be at the output. If the voltage stays low, and does not easily go to 14v at higher revs, then the alternator (stator and/or rotor) would have to be suspect, (along with the always possible bad wiring condition). People have used these cheap rectifiers with great success on some of the bikes (KZ's) that have separate regulators and rectifiers. It's not a permanent device, so reliability won't be a concern with it.

This probably costs less than the batteries for a multimeter.


This issue is the time it takes to get. China can take a month. For another couple bucks, you might find one in the U.S. that you can get in less than a week.

Here's one.


I consider these things as tools for troubleshooting.

Dead battery this morning. Put the bike on the charger 7:00 AM, tried again to start it at Noon. Between the time I disconnected the charger and pushed the bike out of the shed the battery was only at 11 volts.

Maybe I need to pay someone to figure this out. I can't seem to get to the bottom of these electrical woes.

Sound like you need a battery. A dead, shorted or sulfated cell can act like this. Does it drop like that out of the bike?
Steve

Perhaps. The battery is new though.

I'd charge it out of the bike, let it sit, then test it. I've had new bad batteries before.
Steve