Hello everyone. My family has a 16" aluminum boat with a 1980 Johnson 85hp outboard motor (J85TLCSA) that up until recently was expertly maintained. Then due to my father passing away, it has seen little use the past few years. But last year I had a Marina do a complete clean/de-winterize of it, and we got it started with only a little trouble. It idled well and run full open throttle just great. So we took it back to the marina for winterization, and left it in a covered carport over the winter.
Well this year when we launched it and tried to start it up it was stubborn. Finally we cranked it and played with the choke lever and whammo, it roared to life and then pegged the RPM gauge. I immediately backed off the choke (which I understand is just a way to throttle it in neutral) but the RPMs remain pegged at about 8K so I cut the power. I repeated this a few times and let the engine warm up a bit. It was running rough and the high RPMs were scaring me ... so I shut it down, popped the top and inspected everything.
Once the cover was off it started at a low idle and was well behaved. We let it run for about 30 minutes and every so often would ramp the choke up and down, throttling it between 1K to 5K and back down without incident. Also tried turning it on and off a few times. Finally we applied carb cleaner and then inspected the throttle linkages. There was some play, but nothing seemed like it would be problematic.
So we carefully took it out and drove it for about 30 minutes. It ran fine, turned around and came back. As we approached the Marina and I backed it off into Neutral, the shifter was a bit sticky. So I pushed it past the catch and as it hit neutral the engine decided to go full open throttle again. I jiggled the throttle to no avoid, and eventually had to cut the power with the key. Starting it back up pegged the RPM gauge even with the cover off this time.
Upon starting the RPM was at about 3K, and it was rising about 100 RPM every few seconds. Eventually the gauge would bug out and I'd just cut it to be safe.
With the engine off I observed the linkage movement as I throttled the shifter forward. There is a displacement of approximately 2", so I'm guessing externally visible cable and mechanical parts are not to blame. I'm just not able to see anything catch, or hang, or fail to retract.
I lack the mechanical background that my Dad had, and seeking help from a Marina/Mechanic right now isn't looking good due to the months-long backlog of work they all have. Any thoughts on what I could try to resolve this issue?
And when dealing with these kinds of engines, what guidelines exist for redlining them? Should I do everything to completely avoid it, or is some high RPMS for a minute or so while testing acceptable?
Thank you for any insight you can provide me as I dive into learning about this engine!
Well this year when we launched it and tried to start it up it was stubborn. Finally we cranked it and played with the choke lever and whammo, it roared to life and then pegged the RPM gauge. I immediately backed off the choke (which I understand is just a way to throttle it in neutral) but the RPMs remain pegged at about 8K so I cut the power. I repeated this a few times and let the engine warm up a bit. It was running rough and the high RPMs were scaring me ... so I shut it down, popped the top and inspected everything.
Once the cover was off it started at a low idle and was well behaved. We let it run for about 30 minutes and every so often would ramp the choke up and down, throttling it between 1K to 5K and back down without incident. Also tried turning it on and off a few times. Finally we applied carb cleaner and then inspected the throttle linkages. There was some play, but nothing seemed like it would be problematic.
So we carefully took it out and drove it for about 30 minutes. It ran fine, turned around and came back. As we approached the Marina and I backed it off into Neutral, the shifter was a bit sticky. So I pushed it past the catch and as it hit neutral the engine decided to go full open throttle again. I jiggled the throttle to no avoid, and eventually had to cut the power with the key. Starting it back up pegged the RPM gauge even with the cover off this time.
Upon starting the RPM was at about 3K, and it was rising about 100 RPM every few seconds. Eventually the gauge would bug out and I'd just cut it to be safe.
With the engine off I observed the linkage movement as I throttled the shifter forward. There is a displacement of approximately 2", so I'm guessing externally visible cable and mechanical parts are not to blame. I'm just not able to see anything catch, or hang, or fail to retract.
I lack the mechanical background that my Dad had, and seeking help from a Marina/Mechanic right now isn't looking good due to the months-long backlog of work they all have. Any thoughts on what I could try to resolve this issue?
And when dealing with these kinds of engines, what guidelines exist for redlining them? Should I do everything to completely avoid it, or is some high RPMS for a minute or so while testing acceptable?
Thank you for any insight you can provide me as I dive into learning about this engine!