"I recently acquired a 1989 2
"I recently acquired a 1989 20' pontoon boat with a 40hp Mariner (40ELTO 6E9 L 500783) which my guess is that it is a 1988-89, yamaha made for merc. The oil injection system, surprisingly, worked right up to the time I removed it and threw it in the trash. Here is the delema I am having...When the motor is running, out of gear, I can hit the throttle and the motor "raps" out like it should (tach not working yet, but I would guess in the 5000 rpm range). In gear, (in the river) WOT is maybe 1500-1700rpm. Other than the interior stuff and me there is no other added weight to the boat. The prop that is on it now is a 48-73132a40, which translates (I think) to a 11 1/4 - 10" pitch, a few of the prop calculators out on the net suggest a 10 7/8 X 11. Which I think will probably put me in about the same place I am now... Smaller prop spins faster, but more pitch slows it back down = same rpm range/speed (maybe 8mph). In your opinion does this sound like I'm on the right track?
Also, the motor runs great...no sputtering/missing while underway, plus the great throttle response while not in gear tends to push me away from an engine issue.
I haven't been able to find any info on this motor like manufactures suggested WOT on the net (guessing around 5000). Any help there would also be greatly appreciated.
Much thanks to you if you can be any help!"
"I recently acquired a 1989 20' pontoon boat with a 40hp Mariner (40ELTO 6E9 L 500783) which my guess is that it is a 1988-89, yamaha made for merc. The oil injection system, surprisingly, worked right up to the time I removed it and threw it in the trash. Here is the delema I am having...When the motor is running, out of gear, I can hit the throttle and the motor "raps" out like it should (tach not working yet, but I would guess in the 5000 rpm range). In gear, (in the river) WOT is maybe 1500-1700rpm. Other than the interior stuff and me there is no other added weight to the boat. The prop that is on it now is a 48-73132a40, which translates (I think) to a 11 1/4 - 10" pitch, a few of the prop calculators out on the net suggest a 10 7/8 X 11. Which I think will probably put me in about the same place I am now... Smaller prop spins faster, but more pitch slows it back down = same rpm range/speed (maybe 8mph). In your opinion does this sound like I'm on the right track?
Also, the motor runs great...no sputtering/missing while underway, plus the great throttle response while not in gear tends to push me away from an engine issue.
I haven't been able to find any info on this motor like manufactures suggested WOT on the net (guessing around 5000). Any help there would also be greatly appreciated.
Much thanks to you if you can be any help!"
