'94 60 HP Intermittent Spark

[IDFISHER]

I'm having an intermittent spark issue on my 3 cyl '94 60 HP Johnson. I took it to the lake earlier this year and it ran great the whole day. The next time I took it out I couldn't get it to get up on plane, was only doing about 5 MPH at WOT. However, after about 10 minutes of warming up it finally kicked in and i was able to go close to 30 MPH for a 10 minute run. Fished for a while and then started it back up again, same thing but this time it only took a couple minutes before it kicked in and was able to cruise back to the ramp.

Next time out, same story. 10 minute warm up before i could go full speed

Next time out, fired right up and ran great from right from the dock. But then after fishing for an hour, could not get it to go over 5 MPH again.

Came home, did a cylinder drop test and the bottom cylinder is getting no spark. Swapped spark plugs, same thing, inspected the plug wire and both ends look good, tested the coil and got 245 ohms. That's about the extent of my electrical system knowledge on an outboard so i'm not sure where to go from here.

After one of the first runs with problems I did notice the lower mount on the power pack was cracked and loose so I JB Welded it back together and it's solid now but the problem persists.

Any other thoughts?

 

[jakedaawg]

I think you should start over with the diagnosis.


Step one is a compression test, no sense wasting time on failing block. Testers can be rented or loaned at parts stores.

Step two is an open air gap spark test set at 7/16ths inch with appropriate tester commonly available at parts stores for a few bucks.

Report back those results and someone will tell you how to do the next steps. How to tell if it's a pack or coil or trigger.

But even if it does not make sense, those two steps must be done first to not waste money or time.

 

[oldboat1]

^^Good advice. Also might check the operating temp on your motor (may be running hot -- around 160F.)

 

[IDFISHER]

Compression is 110/105/110.

Spark jumps the gap easily on top 2 cylinders. Spark plug from bottom cylinder jumps great when hooked up to top 2.

I don't have a infrared thermometer but just by feel it doesn't seem to be running overly hot.

 

[oldboat1]

Temp is probably good (160F is too hot to touch, at least for very long). You might check continuity of the coil to plug wire for the lower cylinder. Metal spring connector to metal spring connector. Should be full continuity.

 

[IDFISHER]

I broke down and took it to the shop. They stated it's a bad power pack. They're replacing it and i should have it back in about 7-10 days.

 

[IDFISHER]

Just to close this thread out. I got my boat back from the shop with the new power pack. I've taken it out twice and it's running better than it ever has. Starts easy, idles perfectly, runs great at all RPMs.

 

[oldboat1]

Good ending. (Good shop!)