1998 Tracker by Mercury

[RealSeabee]

1998 Tracker by Mercury - 40 HP


Symptoms - I can get the boat (16.5' Tracker) up on-step and running at a steady 4,000 RPM's. It seems smooth through acceleration but can only maintain RPM's for approx 45 seconds then it starts to drop-off. It seems to settle at about 3000-3100 RPM's but since it is between on & off of step, I do not leave it there very long. If I bring the boat back to Neutral/Idle for a minute then accelerate again it will get back on-step but it holds it for only 35 seconds or so.

Work completed by a certified Marine Mechanic over the last 30 days:
1. Complete tune-up w/ new plugs
2. Carb rebuild kit with ALL new hoses and inlet's
3. Replaced fuel lines and bulb
4. New Control Box and cables

The boat has a mounted 12 Gallon tank. There have been periods where the boat has not been run so I figured I would rule out a fuel issue. Today I got a new 6 gallon tank and changed the motor over with fresh fuel and oil. Same symptoms as already stated. All totaled, I have about 700 in repairs at this point.

Any advice, angles or ideas are appreciated.

Thank you,
R/
Dave

 

[RealSeabee]

1998 Tracker by Mercury

Does anyone think that the issue might be Head related?

 

[PGFISHER]

Re: 1998 Tracker by Mercury

Is your fuel tank properly vented?

 

[mikeneal]

Re: 1998 Tracker by Mercury

Defiantly sounds like fuel delivery problem. Fuel pump rebuild, rebuild kits are easy and cheap and older ones don't get along well with newer ethyl fuel. If you can take someone along for sea trail have them pump primer bulb to see if it alters the mis. You can also replace a short section of fuel hose between pump and carb to look for bubbles. Same with the suction side between pump and tank.