Stator Resistance??

[nsoley]

Interesting one... Bought a 1994 SeaDoo SPi with the 587cc engine. As part of the full restoration I am doing, I wanted to ensure (before the engine goes back in) that the Stator resistance checked out OK as replacing the stator when the engine out is likely easier.

I took my multimeter, put it on the 200Ω setting, placed the red and black probes to the YELLOW and YELLOW/BLACK wires. The reading came back 4.3Ω when the specification is 0.05Ω-0.6Ω

Am I missing something here? IMG-8886 shows the multimeter setting. IMG-8885 shows the measurement.

Would the heat shrink play a part in higher resistance? (IMG-8887) I am debating cutting the wires, and measuring bare copper on both YELLOW and YELLOW/BLACK wires without the heat shrink and male terminal. Thoughts?

 

[artr]

If you just short the leads of your meter, what is the reading? That number should be subtracted from the 4.3 ohms. I have the same meter. I think it is supposed to read 0.0 when you short the leads on the 200 ohm range. The reading you get is probably the resistance through the leads.

 

[nsoley]

@artr you’re correct. The multimeter has 1.4 Ω of resistance in just the probes alone as when I touch the red and black probes together, the multimeter reads 1.4Ω

So my previous reading of 4.3 Ω should really be less 1.4 Ω, which is 2.9 Ω….

2.9 Ω is still high but not an OPEN or OL condition… thoughts?

 

[artr]

I do not know how difficult it is to open the magneto cover and get to the coil that those wires are connected to and inspect internal connections. Before doing that I would start by checking your meter by removing the test leads and taking a short U shaped copper wire or a paper clip and directly shorting the 2 inputs where the test leads connect. If you still don't get a 0.0 reading on the 200 ohm scale, then you probably need a more sensitive or higher quality meter to make the measurement. You could also try a fresh battery in the meter.
If you get the 0.0 reading then you can examine those male terminals at the wire ends. If they are hollow at the top or you can see exposed copper wire under the shrink wrap, you can try touching the wire directly with the test lead or a straight pin or paper clip to tell if the crimped terminal is adding some resistance. You could also pierce the wires with a straight pin or remove a little wire insulation below the crimped terminal to make the same measurement but if the crimped terminals are not adding any resistance put something to re-insulate the opening you made like silicon sealant.
Like you said, it is not an open circuit and your last measurement is only a couple of ohms away. Also, I do not think I would completely trust a reading from that meter compared to a lab quality one. If you know the battery was charging before you did your rebuild, it might not be worth bothering with, especially if it is a lot of trouble and expense to replace.
While I do not think a couple of ohms would make a difference given the meter you are using, maybe someone who has done a lot of testing and replacing of stators can offer an opinion as to what they would do.

 

[nsoley]

Hi @artr
Thanks for the feedback. I would think touching the two leads directly together and getting 1.4 Ω means that if i were to add any sort of material (I.E. paperclip or copper wire) between the two leads, that 1.4 Ω reading would only go up???

The battery in the meter was new as of yesterday so I am ruling that one out.

I would have to take the flywheel cover housing off (easy to do, couple of bolts) however, once I am in there, the flywheel itself does cover the Stator quite well and Im not sure if Ill be able to get the multimeter in there.

I do like your idea of just piercing the wires and getting the multimeter probes onto bare copper from the outside. I might do this......

The ski was bought 2 weeks ago really in an unknown condition other than a compression test of 155 psi on each cylinder. Again, this is all precautionary before the motor goes back into the hull. I am leaning towards "it is OK" as the resistance is so low and it is not an Open Circuit.

The last part of this mystery is that the grounding post for the spark plugs is not present, which means this flywheel housing cover has been opened / removed before. (see attached image of an example image off of Google) I am wondering if mine is an aftermarket stator with different resistance measurements that would differ from the shop manual.... Im wondering if there is any visual indication of the wires / terminals that this might be aftermarket? The machine is 27 years old, so I wouldn't be surprised if the engine is a re-man or if the stator has been changed before.

 

[artr]

At the beginning I was suggesting removing the test leads from the meter and shorting directly across the input jacks where the test leads plug in with a short U shaped wire. This would confirm that the 1.4 ohms is from the test leads (which is most likely) and not inherent in the meter itself.

 

[etemplet]

If you are not getting the proper reading you have a problem. Is there a changes your coils are damp? You have to make sure they are dry. I just tested two coils tonight. Both were at .3 to .4 ohms and 53 to 55 ohms on the two black wires.

 

[nsoley]

So I may have gotten a clue into this mystery last night.

See attached photo. I am working on a 1994 SPi, which DOES NOT have a white wire coming out of the stator by design. Physically, this stator DOES have a white wire that was cut / snipped. This leads me to believe the stator assembly was replaced and came out of either a 1993 or 1994 XP with a 657 engine as they had this additional white wire.

Would this different stator have a different resistance value?