Tweet
I have a question for you guys about a boat I recently purchased, a 2002 Boston Whaler, with a 2003 Yamaha 90hp 2 stroke Outboard. The engine ran great the first few times I had it out, but always seemed sluggish, I was getting 4600 rpm and 36 mph at WOT, but it would take a while to get up there, it didn't seem to be very responsive. Then I had it out for an extended cruise on maybe the 4th time I had it in the water this season since buying it. Thing was running great, right up until it died. I had been running across a lake, probably ten minutes at around 4000 rpm, slowed down to enter a channel, saw some big waves coming so put the throttle back down to get up on plane to hit the wakes, and had nothing, no rpms. Put the throttle down to the floor and got maybe 1800 rpms and it slowly puttered out and died. I quickly switched fuel tanks and tried to get it started again, motor ran for maybe a minute, same issue, max 1800 rpm and then died. Couldn't get it started for longer than 2 seconds again after that. I added oil, made sure that the tanks were vented (they were), tried the priming bulb, tried both fuel tanks again. Nothing dead in the water. I then raised the engine up out of the water to check the prop and all the oil alarms went off and the buzzer. But the engine had oil in the tank. Not sure what happened there, I had to get towed back. The next morning I tried firing it up in the driveway and it fired up first try and appeared to be running strong. I took apart the internal fuel filter, and it was slightly dirty but certainly not clogged.
One thing I have noticed is that when I pump my priming bulb it never got hard. I know that it won't stay hard when the engine is running, but it never gets hard with the engine shut down. I was pumping the priming bulb the other morning and listening to the fuel pump and I could hear the fuel flooding through the fuel pump. So I replaced the internal Fuel filter screen, fuel/water separator, the diaphragm driven fuel pump, fuel lines, primer bulb, fuel tank (had a new one ordered anyways so went ahead and put it in), and the spark plugs (previous owner hadn't changed them in a while.).
I just had it out for the first time today after several tests running on muffs in the driveway. It ran great for about an hour. Much more responsive, and was getting about 4700 rpm and 37 Mph at WOT. I was running it at around 3900 rpm and cruising down the lake, when I saw some nice flat water, so I punched it. Was turning around 4600 rpm and then all sudden I felt something give, and had immediate power loss. This was different than last time, as last time I didn't see the power loss until I tried to throttle back up. This time I was at WOT and It almost felt like I hit something, like a sudden **** and then power loss. This time the engine stayed running and I could power her to about 2200 RPM and get about 8 mph out of her, but if I put the throttle to the floor I would get a gradual acceleration until about 3000 rpm and 15 mph. I didn't push it and got back to the dock. I checked over all my work and there are no smoking guns. So I turned the motor on and off a few times, then tried the choke, the motor would rev up very quickly to 3000 rpm, nothing like what it does in gear. It sounded good so I left the dock and got the same issue, motor would run but rpms would build super slowly nothing like the responsiveness I felt earlier in the day. So I went back and got the boat on the trailer.
Any thoughts as to what gave or what I can do to fix this?
Comment