canadaboy25
New member
Hey everyone, I have a 1980 Johnson 85hp v4 outboard which has no power from a standstill. When the boat is stopped and is put to full throttle, it takes off alright but will not go all the way to full speed. After a while, it seems as if another cylinder kicks in as the motor immediately revs up and goes to full speed. It runs at full speed perfectly fine, it is just getting to full speed which is the problem.
Initially, I thought there was a fuel problem so I cleaned both carbs out real well but it made no difference. The throttle shafts had a lot of wear between them and the carb body so I got two different carbs from a '93 90hp Evinrude and tried those. It seems to have helped it idle a little better but the full speed problem is still there. All the fuel lines are new, the fuel screen is clean, and the the pump is working well. I think I have ruled fuel out as the issue.
I put the motor on the garden hose and started it up and started pulling off spark plug wires to see if I had a bad cylinder. Removing the top right wire makes a very noticeable difference as the motor slows right down, runs very rough, and stalls eventually. The bottom right cylinder is similar, however it does not run quite as rough and doesn't usually stall. However when unplugging the top or bottom left pug wires there is basically no change at all. If you really listen there is a very slight change but nothing compared to the right side. When the wire is put back on the spark plug, the motor revs up for a split second and then back down to where it normally is. While I have the wire unplugged there is a strong spark between the end of the plug wire and the pliers I am holding the entire time and it does make a very slight difference to the way the motor runs so it's not completely missing spark.
I did a compression test and the numbers were 110, 115, 115, 120. They're not perfect but should not be causing this issue. The top right cylinder that seems to be contributing the most is at 115 and one of the cylinders on the left side that seems to be causing the problem is at 120. So it isn't a compression problem.
I swapped the powerpacks from left to right to see if the problem moved but it was exactly the same. The right side was still running well and the left side wasn't making much difference when unplugged.
I swapped the two coils from the left side to the right side and vice versa but still no change at all.
I'm not sure what else to try as I have ruled out fuel and compression and the way it all of a sudden finds its power and gets up to speed seems like an electrical issue to me. The powerpacks and coils have been ruled out as problems so the only part left I can think of is the stator. However, how would this cause a problem on only one side of the motor?
Any advice is appreciated.
Initially, I thought there was a fuel problem so I cleaned both carbs out real well but it made no difference. The throttle shafts had a lot of wear between them and the carb body so I got two different carbs from a '93 90hp Evinrude and tried those. It seems to have helped it idle a little better but the full speed problem is still there. All the fuel lines are new, the fuel screen is clean, and the the pump is working well. I think I have ruled fuel out as the issue.
I put the motor on the garden hose and started it up and started pulling off spark plug wires to see if I had a bad cylinder. Removing the top right wire makes a very noticeable difference as the motor slows right down, runs very rough, and stalls eventually. The bottom right cylinder is similar, however it does not run quite as rough and doesn't usually stall. However when unplugging the top or bottom left pug wires there is basically no change at all. If you really listen there is a very slight change but nothing compared to the right side. When the wire is put back on the spark plug, the motor revs up for a split second and then back down to where it normally is. While I have the wire unplugged there is a strong spark between the end of the plug wire and the pliers I am holding the entire time and it does make a very slight difference to the way the motor runs so it's not completely missing spark.
I did a compression test and the numbers were 110, 115, 115, 120. They're not perfect but should not be causing this issue. The top right cylinder that seems to be contributing the most is at 115 and one of the cylinders on the left side that seems to be causing the problem is at 120. So it isn't a compression problem.
I swapped the powerpacks from left to right to see if the problem moved but it was exactly the same. The right side was still running well and the left side wasn't making much difference when unplugged.
I swapped the two coils from the left side to the right side and vice versa but still no change at all.
I'm not sure what else to try as I have ruled out fuel and compression and the way it all of a sudden finds its power and gets up to speed seems like an electrical issue to me. The powerpacks and coils have been ruled out as problems so the only part left I can think of is the stator. However, how would this cause a problem on only one side of the motor?
Any advice is appreciated.