Hi all,
i just bought a very nice boat with a Yamaha four stroke outboard engine, F9,9CE (66N A0). But unfortunately the engine is not running as it should. It doesn't run smooth and in my opinion the fuel mixture is too rich or to lean. the airfilter has been taped for 40% and the air screw is pretty far open. This only must be 1,5 turns, right? (now almost fully open). When you give throttle, the engine drops. if you carefully give throttle, then it will go up.
the airfilter, should not been taped and the air screw not wide open. So i am wondering what is wrong.
1. Could it be the fuel pump?? maybe i have to change the diapragma? There are no holes in it, it only ribles a little bit, like the rubber is not flat/stiff anymore at that point. Maybe that is the problem, since the suction is not that strong now?? could this be the problem??
2. or could the problem be at the electric shoke? maybe that one is broken and just gives too much fuel continuously? can i check this? and how?
any other ideas?
i checked all the fuel lines and changed the fuel tank and the problem still occurs.
Hopefully somebody can help me out!
thanks in advance!
gr. Rutger
i just bought a very nice boat with a Yamaha four stroke outboard engine, F9,9CE (66N A0). But unfortunately the engine is not running as it should. It doesn't run smooth and in my opinion the fuel mixture is too rich or to lean. the airfilter has been taped for 40% and the air screw is pretty far open. This only must be 1,5 turns, right? (now almost fully open). When you give throttle, the engine drops. if you carefully give throttle, then it will go up.
the airfilter, should not been taped and the air screw not wide open. So i am wondering what is wrong.
1. Could it be the fuel pump?? maybe i have to change the diapragma? There are no holes in it, it only ribles a little bit, like the rubber is not flat/stiff anymore at that point. Maybe that is the problem, since the suction is not that strong now?? could this be the problem??
2. or could the problem be at the electric shoke? maybe that one is broken and just gives too much fuel continuously? can i check this? and how?
any other ideas?
i checked all the fuel lines and changed the fuel tank and the problem still occurs.
Hopefully somebody can help me out!
thanks in advance!
gr. Rutger