'74 Johnson 9.9 misfire

[johnnyb563]

Guys,

I just bought this 9.9 last week. I checked it over well, played around with it in the garage and everything seemed to be working fine. I took it out today and it ran great for about 1/2 an hour throughout the whole power range, then it started to lose power and miss. The plugs look fine, and it seemed like the carb float was sticking. I 'm just wanting to check with some guys with some good outboard experience for pointers. I have a lot of engine knowledge, and a little on 2-cycles, but this is my first outboard. Generally I think that most engines are the same, but they all have their little quirks.

Anybody have any other suggestions?

Thanks

 

[rgresh2]

Re: '74 Johnson 9.9 misfire

i have a 6 hp seahorse and mine started doing the same when i was trolling and then started dying cause i forgot a very simple thing :redface: and that was to open the vent on the gas tank you might check that first

 

[johnnyb563]

Re: '74 Johnson 9.9 misfire

Nope. That was the first thing I did after I started the engine. Like I said, it ran for about 1/2 an hour without any problems. I'm taking the carb off today and checking it out. I'm pretty sure the float was sticking. All of the engine ignition system is brand new, and I already double checked all connections again. (unless I have a coil that is no good from the box) I was just looking for some common carb or engine related problems that may be specific to these smaller Johnson models from the mid '70s.

Thanks for the reply though!

 

[johnnyb563]

Re: '74 Johnson 9.9 misfire

Problem turned out to be a loose plug wire from the coil. The wire pulled right out of the coil when I touched it. I took the other coil off and found that wire pulled right out as well. I had to epoxy the wires into place. It ran fine all day.