Not firing on all 4 cylinders

[Shellfish]

I have a 130 hp Johnson 1996. The problem is when I fire her up she sometimes is missing on one cylinder. When I head out in to the harbor on 3 cylinders and rev. the motor she will usually catch after a short run and then I have no problem. I went out the other day and the usual missing cylinder occured
again but I couldn't get the other cylinder to catch. I switched to my trolling motor and fished for the next 3 hours. When I fired up the big engine all 4 cylinders were working. Does anyone have an idea
on where I should be looking in this motor to solve this problem???

Thanx, Shellfish

[KevinM]

Plugs are fouling

[Whaler27]

One of the coils is probably going bad.

[ndb8fxe]

I think this is relatively normal in these engines. I had a rude 90 of that vintage and it would always do that although it wouldn't take that long to catch all four. Normally I'd back the trailer in and start the engine it would run on three. By the time I was ready to back the boat off it would be running on four. It would run on three maybe 30 seconds or so before it would run correctly.

I also had an older Johnson 70 three cylinder. That one would run on two for a minute or so before the third cyl. would catch. I think its a combination of older carberated technology, fowling plugs easier. Once the head would heat up the plug unfowls.

Just a guess, but I think it's somewhat normal on the older engines.

[clemco2]

Check your sparkplug wires, its easy to lose contact between the wire and the boot when you pull them off the plug. I've had this happen on mine.

[basstardo]

Your condippity pin came off the jam flange...

Actually, I agree with the coil deal. I had the same problem on my 90 Evinrude.

[Shellfish]

Is there a way I can test and determine which coil might be failing. As to having fouling plugs. I failed to mention that I change plugs every 5 th trip. Those plugs are good. I was kind of feeling that it might be a coil problem. I needed some other reassurrance before I started digging in to it.

Shellfish

[baitrunner]

One way to figure out which cylinder isn't firing would be to pull a plug wire while it's running poorly. If it changes the way it runs, that one is firing. When you find the one that doesn't make any difference whether it's plugged in or not, you've got the culprit.