Sorry for the title, hard to summarize.
Background: Motor is a 1997 Johnson 9.9 2-stroke short shaft: J10REUS. I just bought it from someone who used it as a kicker motor. Hasn't been used since 2008. Replaced the lower unit oil. It was dark, so I'm glad I did it. Pee stream is fine so I did not replace the impeller.
Short version: Motor ran fine for 20 minutes. After that, the motor decided to start dying whenever i opened the throttle up in gear. Lasted about 15 minutes. Ran it for 20 minutes after with no problems before going home. Ideas?
Long version:
Anyway. Ran it in a tank for awhile, worked fine. Took it out on my boat (14' alumacraft). The thing just flies! My other 10hp motor has nothing on this Johnson. Drove around for like 20 minutes with it. Then, my problem started occurring.
The motor slowed, then died while driving. The same way it would if it ran out of gas. But the priming bulb was hard. I kept starting it (which was always easy) and i had absolutely no problems starting. It would idle fine with no indications of any problems. However, when I would shift it (and give it more gas due to being in gear) it would die. I would start it, let it idle for awhile (which was absolutely great) and then put it in gear, and when I tried to open the throttle up a bit it would die. Did this a bunch of times. Then tried revving it in neutral. You could rev it up fine in neutral. But if you tried to open the throttle up in neutral and keep it there, it would die.
I tried running with the choke in various positions and it didn't really make a difference, except for what you would expect when you choke the engine (runs harder, more smoke, etc.).
Tried just starting it and letting it idle for a few minutes. Made no difference. Once I would try and hold it at a high RPM, or shift into gear, it would die.
I researched those 60/70's 9.5 johnson motors one time and heard that something similar happened due to exhaust leak inside the motor casing. I took the cover off just in case. Did not produce immediate results.
Eventually the problem just "went away" (at this point the cover was still off, but had been for awhile). No idea why it went away. Ran the motor for another 20 minutes until it got dark without problems.
An important thing to note here is that the fuel line squeezer was always hard. I ran a '67 evinrude fisherman 6 off of the same tank and fuel line and it had a problem where it would die like this due to a hole in the fuel line-- so I know very well the symptoms of that problem, and it was not that. The primer ball was definitely as it should be.
Any idea what happened? Sorry for writing a book, but I wanted to give all of the details. I really am clueless. It runs so great aside from all of that. But I'm a little worried about what happened here. And I'm nervous to bring it into a mechanic if it's an on-and-off sort of thing. If you need other details please ask. I'm not sure what might apply. Happy to look at whatever you need.
Thanks in advance,
Scott
Background: Motor is a 1997 Johnson 9.9 2-stroke short shaft: J10REUS. I just bought it from someone who used it as a kicker motor. Hasn't been used since 2008. Replaced the lower unit oil. It was dark, so I'm glad I did it. Pee stream is fine so I did not replace the impeller.
Short version: Motor ran fine for 20 minutes. After that, the motor decided to start dying whenever i opened the throttle up in gear. Lasted about 15 minutes. Ran it for 20 minutes after with no problems before going home. Ideas?
Long version:
Anyway. Ran it in a tank for awhile, worked fine. Took it out on my boat (14' alumacraft). The thing just flies! My other 10hp motor has nothing on this Johnson. Drove around for like 20 minutes with it. Then, my problem started occurring.
The motor slowed, then died while driving. The same way it would if it ran out of gas. But the priming bulb was hard. I kept starting it (which was always easy) and i had absolutely no problems starting. It would idle fine with no indications of any problems. However, when I would shift it (and give it more gas due to being in gear) it would die. I would start it, let it idle for awhile (which was absolutely great) and then put it in gear, and when I tried to open the throttle up a bit it would die. Did this a bunch of times. Then tried revving it in neutral. You could rev it up fine in neutral. But if you tried to open the throttle up in neutral and keep it there, it would die.
I tried running with the choke in various positions and it didn't really make a difference, except for what you would expect when you choke the engine (runs harder, more smoke, etc.).
Tried just starting it and letting it idle for a few minutes. Made no difference. Once I would try and hold it at a high RPM, or shift into gear, it would die.
I researched those 60/70's 9.5 johnson motors one time and heard that something similar happened due to exhaust leak inside the motor casing. I took the cover off just in case. Did not produce immediate results.
Eventually the problem just "went away" (at this point the cover was still off, but had been for awhile). No idea why it went away. Ran the motor for another 20 minutes until it got dark without problems.
An important thing to note here is that the fuel line squeezer was always hard. I ran a '67 evinrude fisherman 6 off of the same tank and fuel line and it had a problem where it would die like this due to a hole in the fuel line-- so I know very well the symptoms of that problem, and it was not that. The primer ball was definitely as it should be.
Any idea what happened? Sorry for writing a book, but I wanted to give all of the details. I really am clueless. It runs so great aside from all of that. But I'm a little worried about what happened here. And I'm nervous to bring it into a mechanic if it's an on-and-off sort of thing. If you need other details please ask. I'm not sure what might apply. Happy to look at whatever you need.
Thanks in advance,
Scott
