1976 Johnson 25Hp No Start After Coil Replacement

[peter94]

Hey everyone,

Just wondering if anyone has seen this problem. So my 25HP Johnson (1976) has a misfire under load. Just doing a visual inspection I noticed that both of my ignition coils have cracks running down them. So I ordered 2 new coils from Iboats.com (Sierra #18-5172). Installed both coils, and the engine will not start. No spark (verified with inline spark tester). So I put the old coils back on and it runs. Put the new coils back on and verify the grounds are good, still no spark/no start. What gives? I went and rechecked the part number and the only thing I notice is the picture for the 18-5172 appears to be the coils that I have. However the coils that came out of the sealed Sierra bag look like the picture of the mallory coils for the same application. Either way it should work...

The coils that came out of the 18-5172 bag have "to fit OMC 581-124" stamped onto them.

So I just wonder if they made it into the wrong bag or what. Otherwise they look a little different, but bolt up and connect in the same way as the old coils.

Any ideas?

 

[hawkerjv]

Re: 1976 Johnson 25Hp No Start After Coil Replacement

'76 Johnson.
External coils???
Are the leads going to the coils somehow reversed top to bottom? That would be firing 180 out.
Jim

 

[larryg]

Re: 1976 Johnson 25Hp No Start After Coil Replacement

orange with blue strip goes to top.

 

[peter94]

Re: 1976 Johnson 25Hp No Start After Coil Replacement

Update:

I wound up going to the local marine store and buying some OE Johnson coils. Put them in and it fired right up. Not sure if the ones I recieved from Iboats were a misapplication or something... Strange. They didn't look like the picture on the Iboats website, but they were in the bag with the right part number....

 

[levi_tsk]

Re: 1976 Johnson 25Hp No Start After Coil Replacement

check the windings with a multi meter - could be defective from the factory .... happens sometimes -especially with sierra parts - ask me how i know.....

 

[peter94]

Re: 1976 Johnson 25Hp No Start After Coil Replacement

I actually did do that.

The Old ones were 12,000 ohms.

The new ones that didn't work were 6,000 ohms

The new ones that did work were 12,000 ohms.

Starting to see a pattern here....