TOPIC:

55VAC = junk stator

Oh, and be sure to check the other phases, there are three.

Some manuals have the AC open-load test results flipped between 1-phase and 3-phase. The 1-phase stators will usually get to about 70-75 v AC, but any single pair of a 3-phase will usually get in the 50-55 v AC range. It may be higher on a really good stator/magnet combo, but I don't think I've ever seen the pairs come in at 75 v AC. (This is at the manual's specified 4000 RPM.)

I've seen 3-phase pairs hit about 70 v AC at 6000 RPM.

This is from the 650 manual, and it agrees with the 550 results too. I only have a paper version of the Clymer 750 manual, but it agrees... 4000 RPM should give about 50v AC for each of the possible pairs of stator wires.

In my experience you need at least 70 VAC or more between the 3 legs of the stator. Even at that it doesn't mean you have a good stator because this is an unloaded test. I had TWO stators and both read into this range but neither would put out more than 13.7 volts DC at the battery (under load). I bought a new Rick's stator and immediately got 14.5 volts using the same SH775.

Well, according to all of the manuals, and all of the 3-phase 550's, 650's?, and 750's I've tested, 50 to 55 v AC at 4000 is more than adequate, assuming there is no load related defect. If the testing is done at a much higher RPM, then a higher voltage would be expected. At any rate, we can't conclude both of his stators are "junk", yet. They would have to fail a load test before we can say that.

I just checked my manual. Looks like I'm good.

With the original system, as designed, it would be detrimental, and wasteful, to make a stator that was too powerful for the expected load. An aftermarket supplier may indeed make a more powerful stator. For someone who wants to add lighting etc, that would be the way to go. But on an otherwise stock bike, it would just result in more horsepower being converted to heat.

GPzMOD750 wrote: I just checked my manual. Looks like I'm good.

Do you remember what RPM you used for the tests?

You guys can believe what you want, but I'm telling you that i had two different stators that both tested at 70 VAC with no load and neither would push more than 13.7 VDC to the battery. I was perplexed and wasted several hours testing three different R/R's with the two different stators before giving up and ordering a new stator. In the end I installed a new Rick's stator and instantly got 14.5 VDC with the same R/R.

Not doubting you. Got a link?
Steve

Nessism wrote: You guys can believe what you want, but I'm telling you that i had two different stators that both tested at 70 VAC with no load and neither would push more than 13.7 VDC to the battery. I was perplexed and wasted several hours testing three different R/R's with the two different stators before giving up and ordering a new stator. In the end I installed a new Rick's stator and instantly got 14.5 VDC with the same R/R.

Well, obviously there are other factors that could explain your experience in that case. As you mentioned, load tests are far more telling than an open-load test. Open load tests can only be used to confirm a stator is bad (if it fails the test). Passing the test does not confirm it's good.

I'll hook up the first stator and test again. It actually looks pretty new. I'm not sure whether it's oem or not.

loudhvx wrote:

GPzMOD750 wrote: I just checked my manual. Looks like I'm good.

Do you remember what RPM you used for the tests?

5k