Is there a way to test the transformer on my Inline Six?

[lilboatsman]

Ok, I've acquired a 1972 Merc 1400 inline six that was stripped of it's electronics. It came with a bunch of extra parts including several switch boxes, rectifiers, and transformers. Plus I also have a brand new rectifier and a switch box from my 1250 that I know is good.

I'm wondering, is there a test to find out if my transformer is good? I've read lots on here about how easy it is to fry a switch box if the spark isn't getting through the system. Will a bad transformer do the same?

Thanks to everyone who has helped me thus far.

 

[Laddies]

Re: Is there a way to test the transformer on my Inline Six?

Only by hooking it up to a working switch box

 

[Chris1956]

Re: Is there a way to test the transformer on my Inline Six?

Merc inlines of that era do not have transformers. I presume you mean the ignition coil. It should be red and bulky, if it is original. You may test it with an ohmmeter. The primary winding should be almost a dead short, maybe an onm or two of resistance. The secondary winding should have a couple of hundred ohms resistance.

The good news is that you can get an aftermarket coil for that motor for < $30

 

[Laddies]

Re: Is there a way to test the transformer on my Inline Six?

Chris, apparently Mercury Marine is misinformed as here is a factory build sheet and it calls it a transformer. any AC voltage increasing device is a transformer not a coil.

 

[j_martin]

Re: Is there a way to test the transformer on my Inline Six?

Now, Now boys, don't fight.

An ignition coil is technically, a transformer. There's more to it than that, though, because the induction characteristics are as important to it's function as the transformer characteristics.

Modern nomenclature calls it an ignition coil, or coil for short.

Anyway, primary is about 1 - 2 ohms. secondary should be in the hundreds.

If you touched the primary connections to a 6 volt battery, the secondary should give a smart spark. Certainly wouldn't hurt the coil. If the insulation was failing, that might show up in such a test.

If the primary isn't dead shorted, I don't see how a bad coil could do much harm to the switchbox, so a quick test with an ohmmeter, and then test it live would be the easiest way to what you're trying to accomplish.

hope it helps
John

 

[lilboatsman]

Re: Is there a way to test the transformer on my Inline Six?

Yes, it helped a lot. Primary is about 1.4 ohms and secondary was in the 600's, so I think I've got one that will work. Thanks!

 

[Chris1956]

Re: Is there a way to test the transformer on my Inline Six?

Laddies, My OEM Service Manual for the seventies models called it an ignition coil. How old was the sheet you posted?

 

[Laddies]

Re: Is there a way to test the transformer on my Inline Six?

6-10-93