WalleyeBrian
Member
Greetings,
A friend of mine and I just bought a used boat, with a 93 Mercury 2 stroke, Classic 40 horse outboard (tiller). The first day of use, the Merc ran very smoothly and quietly, had expected torque on throttling up, and reached 30 mph with two people riding in it. The gas was from the previous owner who had not run it much/at all this year, but before purchase we saw it start and run quietly on the water ‘muffs’ and a hose. Not sure how old the gas was, but after a little hard starting and revving, the motor was smooth and not Smokey.
The second day (on a 30 minute trip), it started by performing like the day before (torque-y, quite, responsive, and got to 27 mph with 3 riders). But after about 10 minutes suddenly bogged down and quit - almost like the gas ran out. It did restart after a few tries and after checking fuel (and pressing the bulb of the tank), and checking that there was oil in the injection reservoir. It was still torque-y and regained the speed of 27-28 mph for another 5 minutes when it bogged and quite again.
As the rest of the trip proceeded, it lost more and more of top speed, and bogged 3-4 more times. It didn’t matter if we were going top speed, or moderate speed (i.e., 18 mph), after a few minutes the motor would bog and quit. The final time before our destination it took longer and more tries to re-start, but did restart and we ‘limped’ to our destination where the motor sat for about 1.5 hours before the trip home. Re-starting was very difficult - we almost decided to get the trailer and tow it home but it did finally start (after choking, and not choking, and fiddling with the gear selection to make sure it was in neutral and the throttle position to make sure it was in ‘start’, etc.
The trip home got progressively worse. Top speed at the beginning was about 20 mph and it bogged again within 5 minutes, was hard to restart, and then top speed continued to drop to where it would only reliable run at about 5-6 mph, and it did not run as smoothly or quietly anymore — almost sounded like it was missing a cylinder and or just way too rich. But we could limp home with a louder and rougher but maintainable 6 mph, with about 3/4 throttle —- seemingly way too rich. The throttle response was very slow and hard to achieve power. One more attempt yielded about 18 mph for less than a minute at which time it started to bog and I was able to back off throttle in a way that it did not die. Note that as soon as the motor started having problems, the amount of gas it seemed to use increased dramatically. Tired of traveling a long distance at 5 miles per hour, we finally got assistance to tow the boat home.
At our destination we had re-filled the tank with fresh gas.
We had not had a mechanic check anything, nor change the fuel filter, etc.; and the smooth and responsive performance for the first day (only ran it about 20 minutes) seemed like a service check was not immediately needed — but obviously that did not last more than first day.
A few last symptoms—after it would bog down and stop running, a) often the starter would not even move upon turning the key — we would jiggle the gear selector and/or the throttle to see if that did anything— hard to tell. It would eventually engage the starter, but then, b) upon engaging the starter, it would act a lot like it was flooded — it would quit turning after a few seconds, and not really fire at all until 4-10 turns of the key. When it would turn over a few times then it would sometimes start easily, but more often struggle to life with a little help from the throttle.
Any ideas or hypotheses about causes would be appreciated. Seems like more than one issue. Planning to get a mechanic to service, but maybe there is something obvious or known issues that would be a good place to start. Ready to entertain suggestions.
Thanks!
A friend of mine and I just bought a used boat, with a 93 Mercury 2 stroke, Classic 40 horse outboard (tiller). The first day of use, the Merc ran very smoothly and quietly, had expected torque on throttling up, and reached 30 mph with two people riding in it. The gas was from the previous owner who had not run it much/at all this year, but before purchase we saw it start and run quietly on the water ‘muffs’ and a hose. Not sure how old the gas was, but after a little hard starting and revving, the motor was smooth and not Smokey.
The second day (on a 30 minute trip), it started by performing like the day before (torque-y, quite, responsive, and got to 27 mph with 3 riders). But after about 10 minutes suddenly bogged down and quit - almost like the gas ran out. It did restart after a few tries and after checking fuel (and pressing the bulb of the tank), and checking that there was oil in the injection reservoir. It was still torque-y and regained the speed of 27-28 mph for another 5 minutes when it bogged and quite again.
As the rest of the trip proceeded, it lost more and more of top speed, and bogged 3-4 more times. It didn’t matter if we were going top speed, or moderate speed (i.e., 18 mph), after a few minutes the motor would bog and quit. The final time before our destination it took longer and more tries to re-start, but did restart and we ‘limped’ to our destination where the motor sat for about 1.5 hours before the trip home. Re-starting was very difficult - we almost decided to get the trailer and tow it home but it did finally start (after choking, and not choking, and fiddling with the gear selection to make sure it was in neutral and the throttle position to make sure it was in ‘start’, etc.
The trip home got progressively worse. Top speed at the beginning was about 20 mph and it bogged again within 5 minutes, was hard to restart, and then top speed continued to drop to where it would only reliable run at about 5-6 mph, and it did not run as smoothly or quietly anymore — almost sounded like it was missing a cylinder and or just way too rich. But we could limp home with a louder and rougher but maintainable 6 mph, with about 3/4 throttle —- seemingly way too rich. The throttle response was very slow and hard to achieve power. One more attempt yielded about 18 mph for less than a minute at which time it started to bog and I was able to back off throttle in a way that it did not die. Note that as soon as the motor started having problems, the amount of gas it seemed to use increased dramatically. Tired of traveling a long distance at 5 miles per hour, we finally got assistance to tow the boat home.
At our destination we had re-filled the tank with fresh gas.
We had not had a mechanic check anything, nor change the fuel filter, etc.; and the smooth and responsive performance for the first day (only ran it about 20 minutes) seemed like a service check was not immediately needed — but obviously that did not last more than first day.
A few last symptoms—after it would bog down and stop running, a) often the starter would not even move upon turning the key — we would jiggle the gear selector and/or the throttle to see if that did anything— hard to tell. It would eventually engage the starter, but then, b) upon engaging the starter, it would act a lot like it was flooded — it would quit turning after a few seconds, and not really fire at all until 4-10 turns of the key. When it would turn over a few times then it would sometimes start easily, but more often struggle to life with a little help from the throttle.
Any ideas or hypotheses about causes would be appreciated. Seems like more than one issue. Planning to get a mechanic to service, but maybe there is something obvious or known issues that would be a good place to start. Ready to entertain suggestions.
Thanks!