Hi all,
I have been doing some trouble shooting on a '06 model 50TLR, that is on a little aluminum river boat I bought as a project. I got a great deal, but the guy said the motor was not running, and he had been told it "might" be the CDI unit. I need to explain a little more, or a lot of this wont make sense. This is a 98 model boat with an '06 motor. The guy had bought the boat used, but the original 60HP Yammie had a crack in the crankcase so he replaced the motor with a used 2006 50hp. For the record, the guy knew virtually nothing about boats and was put through the ringer by a few folks. The '06 motor had just been mounted, and had given him fuel related problems more than once. He had the carbs cleaned, and they would just screw up again because nobody had replace the rotten fuel lines...This was pretty much the poor guys experience with the boat. The last time he took it out, he said it ran fine for 5 minutes, then something happened and he had to idle home. He was done with it.
Before I bought it, I checked the compression and the foot, compression was 120 on all three jugs, so I was in good shape. I got the boat home, hooked the earmuffs up to it and started it. It started fine, but the pisser just puked water so I knew it needed a water pump, and I thought that perhaps that is all it needed, as maybe it just shut down on overheat the last time the guy ran it. I replaced the water pump, fuel lines, cleaned fuel tank, filters and went through carbs. Fuel system is good as far as I can tell. First time I launched it, it did just what the guy said....it would die as soon as you hit the gas, at about 1100 rpm. It messed with it and kept trying for 15 minutes, then all of a sudden, it revved up and ran (but wouldn't plane off). I thought that perhaps the fuel pump was acting up so I opened it up to inspect the diaphragms. They werent broken, but I didn't like the way they looked so I ordered a new fuel pump.
2nd attempt, with new fuel pump...same thing happened. No power and would die as soon as you got it to 1100 rpm for 15 minutes. Then all of a sudden it wants to run, but won't plane off. I had my son move up front and tried it again...it planes off, and appears to run fine, except it is only running at 4500 rpm. I can shut it off and restart, and it still seems OK. So we shut it off and fish for 30 minutes, when I restart, its back to not running above idle. Then 10 minutes later, it runs.
Long story short.... The boat will not develop power until something has warmed up good. I believe the reason it only runs at 4500 rpm is because it is severely over propped. At top speed, it is running around 28-30 MPH. although the speedo reads 35 (this is what the guy told me it would run when it worked good). The motor had a whale tail on it when I got it, which I took off. I think the tail helped the boat to plane, but as a couple jack leg mechanics changed the motor out, the prop was never sized correctly for the boat. So, I definitely need to do something with the prop, but I am just stumped about the "not running till it is warm" thing.
Any ideas are greatly appreciated!!
Rich
I have been doing some trouble shooting on a '06 model 50TLR, that is on a little aluminum river boat I bought as a project. I got a great deal, but the guy said the motor was not running, and he had been told it "might" be the CDI unit. I need to explain a little more, or a lot of this wont make sense. This is a 98 model boat with an '06 motor. The guy had bought the boat used, but the original 60HP Yammie had a crack in the crankcase so he replaced the motor with a used 2006 50hp. For the record, the guy knew virtually nothing about boats and was put through the ringer by a few folks. The '06 motor had just been mounted, and had given him fuel related problems more than once. He had the carbs cleaned, and they would just screw up again because nobody had replace the rotten fuel lines...This was pretty much the poor guys experience with the boat. The last time he took it out, he said it ran fine for 5 minutes, then something happened and he had to idle home. He was done with it.
Before I bought it, I checked the compression and the foot, compression was 120 on all three jugs, so I was in good shape. I got the boat home, hooked the earmuffs up to it and started it. It started fine, but the pisser just puked water so I knew it needed a water pump, and I thought that perhaps that is all it needed, as maybe it just shut down on overheat the last time the guy ran it. I replaced the water pump, fuel lines, cleaned fuel tank, filters and went through carbs. Fuel system is good as far as I can tell. First time I launched it, it did just what the guy said....it would die as soon as you hit the gas, at about 1100 rpm. It messed with it and kept trying for 15 minutes, then all of a sudden, it revved up and ran (but wouldn't plane off). I thought that perhaps the fuel pump was acting up so I opened it up to inspect the diaphragms. They werent broken, but I didn't like the way they looked so I ordered a new fuel pump.
2nd attempt, with new fuel pump...same thing happened. No power and would die as soon as you got it to 1100 rpm for 15 minutes. Then all of a sudden it wants to run, but won't plane off. I had my son move up front and tried it again...it planes off, and appears to run fine, except it is only running at 4500 rpm. I can shut it off and restart, and it still seems OK. So we shut it off and fish for 30 minutes, when I restart, its back to not running above idle. Then 10 minutes later, it runs.
Long story short.... The boat will not develop power until something has warmed up good. I believe the reason it only runs at 4500 rpm is because it is severely over propped. At top speed, it is running around 28-30 MPH. although the speedo reads 35 (this is what the guy told me it would run when it worked good). The motor had a whale tail on it when I got it, which I took off. I think the tail helped the boat to plane, but as a couple jack leg mechanics changed the motor out, the prop was never sized correctly for the boat. So, I definitely need to do something with the prop, but I am just stumped about the "not running till it is warm" thing.
Any ideas are greatly appreciated!!
Rich