robert graham
Admiral
- Joined
- Apr 16, 2009
- Messages
- 6,908
Re: 90 hp yamaha 2 stroke need help with wot!!??
Any final resolution to the cause of this WOT RPM issue?
Any final resolution to the cause of this WOT RPM issue?
No way this is OK, you need to be able to achieve towards upper RPM (5800), you may have a rigging problem, is their any obstructions along the keel, like akwardly placed strakes, transducers, etc that could be causing cavitation?...porpoise at 5200+, so maybe you're O.K.
No way this is OK, you need to be able to achieve towards upper RPM (5800), you may have a rigging problem, is their any obstructions along the keel, like akwardly placed strakes, transducers, etc that could be causing cavitation?
My jon boat would be porpoising, chine-walking, out of control at 5800RPM's...
Still think this is a good idea, if you have carb/motor problems and keep running it it can and will cause more expensive problemsIt would be best to have the motor run with the Yamaha test prop to see if the motor is putting out the proper RPM and HP. That can be done on the trailer in the water. If it will not then you have a motor problem, and if it will then you have a boat or set up problem.
Ok hi turn everyone. I rebuilt the carbs and the motor is speced out timming,carbs,cdi etc. I tested the boat on the water and it bogged down when I drop the hammer tach says about 2800 the motor runs like that for 5 mins or so then the motor seems to get up a little bit to 3700 rpm and the boat will get up on plane. The best I can get is 38 to 40 on the tach. All fuel system parts are new tank,lines,fittings, bulb, pump,and fuel. When I rebuilt this motor I reused some of the gaskets and had to make a few could this b my problem??? Is it possible that I am getting water in one or more of the cylinders because of the gaskets? ? I am still getting good compression 100 to 105 on all three and good spark during the spark test. Need good advice please ..
I have done just that I purchased net plugs and ran the motor for a while on the water pulled the plugs on all three. The electrodes. On two of them were a brownish color and one was a lighter tan color. All three the grounds were black and their was oil on all of them what does this mean?? And what about the gaskets should I replace them??