RPM's

[stoked not]

A little help please,<br /><br />I just had a new 2002 125 HP mercury installed on my 18 foot Manatee. I used my original S.S. 17 pitch prop that came off my 115 HP Merc. The local Merc dealer advised me that tmy top end RPM,s should be between 48.5 and 52.5 RPM. At top end my tach reads 5400 RPM's Is this a problem? <br /><br />Can I cause any motor problems?<br /><br />She seems to be holding back a little. Not much difference in speed between 4800 and 5400 rpms. This may be due to the prop, but the motor is also running double oil during break end period.<br /><br />Your thoughts

 

[CAPTBLACKSMARINE]

Re: RPM's

if these rpm readings are wth a normal load in the boat then i would step up to a 19" prop it will give you a little more top end and a little better fuel economy . but if you don't want to come off the cash you can keep running the prop you have just watch the rpm and don't let it go much past the max rpm and you will be fine