I have a Yamaha 90TLRC 3 Cylinder. I started having this problem last year and drained all fuel and did a proper winterize on the boat.
First thing this year, I completely rebuilt carbs with new needle valves, seals etc... They were spotless to begin with. I also replaced fuel filter (water separator). fuel filter in engine, fuel pump and completly flushed any fuel out with brand new non-ethanol fuel.
Engine starts and will run well at 2k all day, but when push throttle to full, it will go to about 4000 rpm (Which is good). I can watch the jets and they are spraying perfectly but then it is like the engine is just flooding out and starts running like crap. It just will stall out and die, even if i back off the throttle down to idle, it will just shut down until i restart it. Once i restart it i have the same problem. The spray out of the jets is perfect and I just came back from the lake with a mechanic my boat and he belives it is the ignition computer. We adjusted the carbs many times to see if adjusting the high-speed mixture would help it and the same problem shows up. My mechanic gave me 2 possible options. Either the power pack or the timing sensor or even possibly a winding on the stator. I am just a garage mechanic but am at wits end on this. I dont want to pay 500 for new power pack to find out that it was not it.
Another weird thing is that randomly the engine runs like crap at low RPM and other times it purrs like a kitten.
I also took a separate can of gas out with us and completely bypassed my in-boat fuel system with the same result.
I tell you the spray out of the jets looks beautiful and does not seem to be shutting down (to be the cause of the decline of power). It almost seems like it is flooding out or the spark just isnt enough to ignite that much fuel.
Compression tests were done and were all around 100-110psi.
So far this is what i have replace
All fuel and oil lines
complete rebuild of carbs 2x
new batery
new plugs
all plugs tested for spark,
compression test.
that is about where i am and ANY help at this time is appreciated. I just want to make sure if i spend 500 for a power pack that it WILL fix my problem
the boat is a 2005 and power pack, stator and timing sensors have never been replaced
Thanks
First thing this year, I completely rebuilt carbs with new needle valves, seals etc... They were spotless to begin with. I also replaced fuel filter (water separator). fuel filter in engine, fuel pump and completly flushed any fuel out with brand new non-ethanol fuel.
Engine starts and will run well at 2k all day, but when push throttle to full, it will go to about 4000 rpm (Which is good). I can watch the jets and they are spraying perfectly but then it is like the engine is just flooding out and starts running like crap. It just will stall out and die, even if i back off the throttle down to idle, it will just shut down until i restart it. Once i restart it i have the same problem. The spray out of the jets is perfect and I just came back from the lake with a mechanic my boat and he belives it is the ignition computer. We adjusted the carbs many times to see if adjusting the high-speed mixture would help it and the same problem shows up. My mechanic gave me 2 possible options. Either the power pack or the timing sensor or even possibly a winding on the stator. I am just a garage mechanic but am at wits end on this. I dont want to pay 500 for new power pack to find out that it was not it.
Another weird thing is that randomly the engine runs like crap at low RPM and other times it purrs like a kitten.
I also took a separate can of gas out with us and completely bypassed my in-boat fuel system with the same result.
I tell you the spray out of the jets looks beautiful and does not seem to be shutting down (to be the cause of the decline of power). It almost seems like it is flooding out or the spark just isnt enough to ignite that much fuel.
Compression tests were done and were all around 100-110psi.
So far this is what i have replace
All fuel and oil lines
complete rebuild of carbs 2x
new batery
new plugs
all plugs tested for spark,
compression test.
that is about where i am and ANY help at this time is appreciated. I just want to make sure if i spend 500 for a power pack that it WILL fix my problem
the boat is a 2005 and power pack, stator and timing sensors have never been replaced
Thanks
