This is a long thread but I tried to explain the whole problems at once. Hi, I'm a 18 year old boy from Turkey and I don't have much experience with marine boats. So my language may not be that flawless and I don't know technical terms that much. I will try to explain my problem in a simplified language.
I have a 1997 Johnson 25 HP 2-stroke outboard motor with BJ25BALEUA model number. We use it for around 15 days a year and then take it back to garage with trailer. The local mechanics and marine shops here don't have much information about old 2-stroke motors so my father and I superficially overhaul it once a year.
Since 2-3 years, the engine has been misfiring or entering Johnson SAFE/SLOW/LIMP mode (I read a few threads and watched a few videos, this issue suits the most.) it is bucking at high rpms. So we changed spark plugs and cleaned carb but the problem persists. The local mechanic said it is stator failure so he changed the stator and fully overhauled the engine but it did not fix the problem. In fact, the engine now goes high rev (probably full rev) on idle without any throttle being applied.
Today, we rope-started the engine in the garage for the first time in a year and it started in the second pull but the flush muff failed so we had no cooling and it was a short test run (around 1 min). The engine went high rev instantly and in a few seconds it started bucking so I started to think that the engine overheat causing safe mode is my case and im positive that the local mechanic made the carb settings wrong, misaligned and set the carb butterfly loose.
So I believe that this is the situation:
Engine starts, the higher airflow causes loose carb butterfly to open more, more airflow causes higher revs, constant high rev causes overheating, overheating results in engine going safe mode.
So there may be a thermostat failure I suppose? And how can I make the right carb settings?
Local stores don't sell most of the Johnson parts, and the ones on sale are really expensive because of the dollar exchange rate. So I need to find the exact issue/faulty part(s) and replace it.
It has been a long thread but I tried to explain the whole problem at once. What should I do? Thanks.
I have a 1997 Johnson 25 HP 2-stroke outboard motor with BJ25BALEUA model number. We use it for around 15 days a year and then take it back to garage with trailer. The local mechanics and marine shops here don't have much information about old 2-stroke motors so my father and I superficially overhaul it once a year.
Since 2-3 years, the engine has been misfiring or entering Johnson SAFE/SLOW/LIMP mode (I read a few threads and watched a few videos, this issue suits the most.) it is bucking at high rpms. So we changed spark plugs and cleaned carb but the problem persists. The local mechanic said it is stator failure so he changed the stator and fully overhauled the engine but it did not fix the problem. In fact, the engine now goes high rev (probably full rev) on idle without any throttle being applied.
Today, we rope-started the engine in the garage for the first time in a year and it started in the second pull but the flush muff failed so we had no cooling and it was a short test run (around 1 min). The engine went high rev instantly and in a few seconds it started bucking so I started to think that the engine overheat causing safe mode is my case and im positive that the local mechanic made the carb settings wrong, misaligned and set the carb butterfly loose.
So I believe that this is the situation:
Engine starts, the higher airflow causes loose carb butterfly to open more, more airflow causes higher revs, constant high rev causes overheating, overheating results in engine going safe mode.
So there may be a thermostat failure I suppose? And how can I make the right carb settings?
Local stores don't sell most of the Johnson parts, and the ones on sale are really expensive because of the dollar exchange rate. So I need to find the exact issue/faulty part(s) and replace it.
It has been a long thread but I tried to explain the whole problem at once. What should I do? Thanks.
