79 115 Johnson power loss- Power Pack ?

[Alpinegold]

Me and ole Joe took my 79 115 J to East Fork and did the Sea Foam thing on the carbs. Man is that stuff good. Starts right up, idles great and runs like a spotted ape.

I'm still concerned about the potential power pack issue. About 4 times out of the last 6 when I get her warmed up come out of the hole and get my plane on, it will suddenly lose about 50 % power and i shut her down to idle. I work the fast idle until I get full power again. Boat takes off and can fish all day and no problems.

The last trip it didnt shut down on the front end of the trip but you could tell it tried to just before I got to the dock. It gave just a couple of small bumps in power and then resumed.

The thing that has prevented me from testing the power pack is the connectors for the jumper. I'm assuming you have to have the B side jumpered togeather when testing the A side of the 2 wire connector comming out of the power pack to I guess those are coils they connect to at the back of the motor.

Does anyone know where to get the connectors to build a jumper for the power pack output voltage test ?

Thanks Alpine

 

[iwombat]

Re: 79 115 Johnson power loss- Power Pack ?

I think what you have is a loose connection someplace. A failing power pack will usually go south when it heats up. Once heated, it continues failing. I'd check all the ground connections and inspect your battery cables before tackling the power packs.

 

[Alpinegold]

Re: 79 115 Johnson power loss- Power Pack ?

That is what I am thinking to. I had an old 69 55 hp johnson and when the power pack went out, it was out. You get a feel for your boat and motor and it feels like a loose connection. I just need to bare down and find it.

 

[tashasdaddy]

Re: 79 115 Johnson power loss- Power Pack ?

remove clean and then tighten all connections. also the pos and neg cables to battery, at battery and motor.

 

[Sherman]

Re: 79 115 Johnson power loss- Power Pack ?

I run this same year 115. After several months of this problem it was solved by replacing the trigger assembly. The wires in it flex a lot and over time will give up. This drove me crazy, the dealer was of now help he sold be a power pack which I still have. I could never get it to fail where I could run any test. Good luck
Sherm

 

[tschamp20]

Re: 79 115 Johnson power loss- Power Pack ?

also check the spark plug boots for arching.seriously!run it on muffs at night so you can see if the spark is coming out from the boot.its free and you might be shocked.good luck.

 

[Alpinegold]

Re: 79 115 Johnson power loss- Power Pack ?

Hey guys, thanks for your suggestions. I'm going to man up tonight and work this thing till I find it.

 

[emdsapmgr]

Re: 79 115 Johnson power loss- Power Pack ?

Take a friend and a timing light with you next time you go boating. When the engine starts to miss, put the timing light on each plug wire. You may be able to determine which wires misfire and isolate your problem. You can move coils and power packs from side to side to see if the problem moves. If you have random misses on all wires, check the stator output. If you don't see any problem, check the fuel system.