Mercruiser 5.0 stalls under load

[Rbrown0873]

Hello - got a 5.0 MPI Mercruiser in a 2011 Lowe pontoon boat with 30 hrs on it. Runs like a top until I start pulling a tube and working it harder and that's when I get two beeps and it starts to sputter. It stays running but there is a loss of power... I slow it down for a bit then it's good to go until I work it harder again. Fuel is new, fuel filter has been changed, engine oil level is good, leg oil level is good. Anyone else experience this or know what might be happening?

 

[alldodge]

get two beeps and it starts to sputter

Thinking it may be getting hot in the exhaust area. With catalysis exhaust it could be many things. In most all cases with CAT motors you have to start with scanning the motor for codes

When was the water pump impeller changed?

Have a motor serial number?

 

[Rbrown0873]

Thanks for the reply

Water pump impeller has not been inspected or changed yet... So few hrs on it that I'm thinking it should be fine but will have a look. It sat for a few years when the previous owner had it so maybe it's sticky from that?

Motor serial number is 1A645648

 

[alldodge]

Impellers need to be changed by time more then hours. If a motor is used year round it better on the impeller then not used. The blades get compressed on one side of the pump and develop a set. Its best to replace the Bravo belt driven impeller at least every 3 years. I replace mine every 2 years

Thanks for the SN, it is a CAT motor

 

[Rbrown0873]

Will give that a go - appreciate the advice!