06 Optimax Pro XS 250 tracker valve

Has anyone replaced on of these?

I am not sure what happened but, Sunday morning, i was idling out of the no wake zone and when I tried to take off, the engine barely started to accelerate then died. I tried to start it again and it just cranked. After a few minutes it started again and seemed to idle ok, tried to take off again and it did the same thing. Got it back on the trailer using the trolling motor and when I got home i put it on the muffs and started it. It ran really rough, cutting out and sputtering then it died again. I took the belt off and the air compressor pulley and it turned smooth with no play and it appeared to be compressing as it got hard to turn then spun around. So I don't think it was the air compressor. The fuel rail diaphragm, or tracker valve, is my next check.I have not checked the fuel pressure or the air pressure because I don't have a gauge to hook up to the valves. Or does anyone have any other suggestions as to what might be the issue?

Good luck.

if your having a problem at idle and acceleration it's most likely the air diaphragm. the tracker valve will create a problem at mid range and above.

start the engine, and depress the schrader valve next to the air regulator.. if fuel spits out... the diaphragm is bad.

I pulled the diaphragm that is on the fuel rail yesterday and it wasn't torn and didn't have any holes. I put it back in and tried to start the engine and it took forever before it fired and then it died right after it fired. I tried to pump the bulb and it would not get firm. I will try and see what the air pressure and fuel pressure shows this afternoon. I have read they should both be right at 80psi.

Steve, is there a diaphragm and a tracker valve? I have looked at a diagram and I see the diaphragm but when I google tracker valve it shows to be the same thing. What I pulled off was on the starboard side fuel rail just above the middle of it.

Lee has extensive knowledge and experience with everything to do with Mercury..if you need anything, be good idea to call him
Custom Marine Service
2429 Fabens Road #200
Dallas, TX 75229
972-484-6505

Did you get this figured out?
Mine was doing the same thing. Google research showed that it's likely the #6 cylinder. Which it is/was on mine. Completely toast.