Yamaha 2008 SX210

[Bryan Halsey]

My STBD engine will get up to 8000 RPM on the hose but will not get over 6500 in the river. Is this an impeller issue? There isn’t a blockage and the clean out plug is intact.

 

[Acard7]

Oil level okay? Air filter good? Last time you changed the spark plugs? Those are the easy fixes. I assume you have the MR1 engines?

 

[Cobra Jet Steering LLC]

Good point about the air filter the mr1 engines clog the filter if you overfill the oil and that obviously chokes the engine at higher r p m's

 

[Bryan Halsey]

Sparks are fresh, oil is good, air filter is good. I’m at a loss to why it shows no issues on the hose but bogs down in the river.

 

[Bryan Halsey]

Sparks are fresh, oil is good, air filter is good. I’m at a loss to why it shows no issues on the hose.

 

[David Martin]

Lots of things can keep an engine from max RPM under load. I would start with the throttle position sensor TPS and the Mass Air flow Sencer MAP both of these sensors could react quite different with no load verse loaded engine. MAP is really important to the fuel injectors output.

Nice thing is you can swap them off the good engine and see if it follows the sensor.