Tweet
I have a 2004 yamaha 90 hp two stoke three cylinder outboard. Its on a 2004 sea pro 18' CC. The motor runs great for the first 20 minutes and then it just idles down to 2,200 rpm's. It will still run and let me idle back to the boat ramp but it won't let me get back up on plane. It will still rev up in reverse or neutral just not in forward. The carbs have been cleaned/rebuilt. A new thermostat, water pump and pressure control valve have all been installed. New spark plugs installed. New fuel lines and fuel filter installed. Non of these things have worked. Any ideas? A mechanic told me something is telling the motor to go into "gaurdian mode". Thanks
-
-
Two events will put a Yamaha 90 into RPM reduction mode. Low oil in the engine mounted main tank and over temperature.
I would not continue to run the motor in the reduction mode. You are at risk of doing some major damage. Find the problem and fix it.
I presume that you do not have a Yamaha tachometer installed that will tell you what is causing the motor to go into reduction mode. This is a worthwhile device to have for this very reason. -
Thanks. I had assumed it was just a faulty sensor and that it was ok to idle back to the boat ramp. The compression is good on all the cylinders and the motor is not over heating. I do have a tachometer on the boat console but its not a yamaha tach. I was hoping I could replace a sensor and fix the problem. Maybe its a more serious issue.Comment
Comment