1972 402 Mercury stator

[buddhapi]

just got my replacement stator today and noticed there is an extra wire compared to my original one. original one has red, 2 yellow, and a dark blue. the new one has a red, 2 yellow, blue and a black one. I don't think the black is ground because there is an ohms resistance reading between it and the red, and it and the blue wires. do I not need the black wire?

 

[Solomon Shaffer]

Re: 1972 402 Mercury stator

I can't help you with the extra wire, but I would say to double check that it is the correct stator. I've had a similar issue when ordering a stator from Mercury. Mind had the right wires, but looked totally different from the old one.

 

[buddhapi]

Re: 1972 402 Mercury stator

now I've been reading that there should be a resistance reading of 5000 ohms between the black and blue wires, and 1500 ohms resistance between the black and the red wires of the original stator, which doesn't have a black wire. maybe it burned off?? the replacement stator readings are to be 50-60%lower. I'm headed to the shop to chack those reading out now. anyone out there with a 1972-1981 40 horse 2 cylinder Mercury ever replace their stator? you know how many wires were on the original? my motor ran like a top this spring, and after I sold it, it pops right off, but barely runs off of idle.

 

[usskydvr]

Re: 1972 402 Mercury stator

From the Mercury Service Manual the stator had two different p/n's. For manual start A-398-4799, for electric start A-398-4770. The resistance measurements should be: Red to Blue = 5K-6.4K Red to Gnd = 45-60.
No other measurements are listed.
I believe the black 'extra' wire is just an additional Gnd (the original stator had a frame Gnd) Check to see the resistance from the new stator frame to the black wire, is is 0?

 

[buddhapi]

Re: 1972 402 Mercury stator

yes. there is no resistance from the frame to the black wire. I can see whay they would want an extra ground wire, as the origianl just grounded through the 4 screws, on top of an aluminum plate. I just didn't want to ground a live wire and burn the new stator up. all the resistance readings are as you said. thank's for your help.