question about new to me yamaha 90hp, '98 model

jbjennings

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Jul 18, 2007
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Motor runs perfectly at all speeds. Compression is about 120psi on all cylinders. That seems kind of lower than I expected but the motor is in like new condition appearance and the way it runs. Are these compression numbers what you guys are seeing on your 90hp yamahas? (Just curious)

Question: The motor is on a 16.5' skeeter bass boat (ss90 model). With my 265lb. dad and myself (230lbs.), the boat goes about 5100 rpm's and about 42mph according to the boat speedometer which in general I find to be less than accurate. Would this prop need a little less pitch to get the rpm's up, or is 5100rpm's okay?
Thanks,
JBj
 
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