2006 Mercruiser 5.0L MPI engine. My main problem is the engine won't go over 2900 RPM, so I can't go faster than about 10 knots and can't get on plane. No alarms, and I am not in Guardian mode.
I've looked at a bunch of possible causes. The cap and rotor look fine (they and plugs were replaced last year). The fuel filter and fuel pressure regulator were replaced. Fuel pressure at idle is ~39-40 psi (Have not checked under load yet). Ran a Diacomm scan and spark advance seems to be adjusting OK up to 2500 RPM. Most of my diagnostics have been done in my driveway since the boat is trailered and it's a production to launch it.
Someone suggested it could be a blocked exhaust. The engine (raw water cooled) doesn't overheat on the water, even at 2900 RPM. It sounds fine also, no missing, knocking etc.
Could a blocked exhaust be the problem? If so how can I test/check for that without tearing apart the engine?
I've looked at a bunch of possible causes. The cap and rotor look fine (they and plugs were replaced last year). The fuel filter and fuel pressure regulator were replaced. Fuel pressure at idle is ~39-40 psi (Have not checked under load yet). Ran a Diacomm scan and spark advance seems to be adjusting OK up to 2500 RPM. Most of my diagnostics have been done in my driveway since the boat is trailered and it's a production to launch it.
Someone suggested it could be a blocked exhaust. The engine (raw water cooled) doesn't overheat on the water, even at 2900 RPM. It sounds fine also, no missing, knocking etc.
Could a blocked exhaust be the problem? If so how can I test/check for that without tearing apart the engine?