2003 225HP HDPI rumbling noise...sometimes

[john90290]

Good morning,

The motor I have above makes this rumbling noise/whining noise as if something is contacting the flywheel but not exactly. I've run with motor cover off and cannot determine the exact location. The weird part is that it does not happen all the time and does not effect the preformance of the motor.

386 hours with a fresh lower unit fluid change and inspection by yamaha dealer where compression was checked and all within range.


Any thoughts?

Thanks in advance.

-John

[boats.net]

Check high pressure fuel pump oil level and check belt. Remove gearcase and inspect drive shaft bushing and exhaust tuner, check prop shaft to see if bent and inspect prop.

[john90290]

Good places to look. I can figure out how to check most of this out but how to I check the high pressure fuel pump?


Thanks,

-John

[boats.net]

On back of high pressure pump there is three 12mm head bolts, bottom one is oil drain, one just above bottom one is full oil level hole, fill with gearcase lube until runs out hole and put plug back in