[muskyscratcher]

I have a 1997 9.9 HP 4 stroke. It's a Mariner/Merc made by Yamaha, in its tenth season, used about 30 hours a season.Bought this motor new. Never a problem. End of last season, oil pressure light went out, indicating low oil pressure. Motor won't run over2,000 RPM per owners manual. Oil level checkedout fine. Changed oil filter and found rubberoil ring sucked off filter and laying in motorhousing. Lucky I spotted it. Changed oil and filter. Still indicates low pressure. Should I expect to replace oil pump in tenth season??? Also, I have always used 10w30 MobilOne Synthetic. Could that be a problem?????Does a 9.9 HP 4 stroke even have an oil pump?

[muskyscratcher]

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[muskyscratcher]

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[muskyscratcher]

Found out a couple thingsThe 9.9 I have is the smaller CC, of the two types made in '97, think it's 209, definitelynot the 323CC. (Has a very small oil filter)I need to find out if oil pressure is lowmechanically, to verify if possibly a pressuresensor problem. Electronically the motor willnot exceed 2000 RPM. How can I get oil pressuretested mechanically? Is there anyway to diagnose without breaking down block???

[muskyscratcher]

Took 9.9 to the shop, still wouldlike any feedback. The Merc machanicand I are worried that problem couldbe trouble finding exact cause/diagnosis.