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Hi everyone,
I have a 1994 3 hp two stroke Yamaha. It is running lean and will stall out at all speeds unless I apply one third choke. What's wierd is when I open the horizontal spring loaded pilot screw (needle valve) a half turn - this has NO effect. In fact, opening or closing the pilot screw one or more turns has no effect at all. Hmmm...
I'm thinking the needle valve (ref. #2 on page 4-3 of service manual) is plugged or something and causing the engine to run lean. My guess is the one third choke compensates (adds fuel) for this. So I guess when I pull the engine off the boat, I will remove the pilot screw and try to clear it somehow (with carb cleaner and/or a small wire?).
Your opinion would be most appreciated. Thank-you.
I have a 1994 3 hp two stroke Yamaha. It is running lean and will stall out at all speeds unless I apply one third choke. What's wierd is when I open the horizontal spring loaded pilot screw (needle valve) a half turn - this has NO effect. In fact, opening or closing the pilot screw one or more turns has no effect at all. Hmmm...
I'm thinking the needle valve (ref. #2 on page 4-3 of service manual) is plugged or something and causing the engine to run lean. My guess is the one third choke compensates (adds fuel) for this. So I guess when I pull the engine off the boat, I will remove the pilot screw and try to clear it somehow (with carb cleaner and/or a small wire?).
Your opinion would be most appreciated. Thank-you.
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