Merc 90HP

[stalker170]

I just bought a 1994 Nitro 170 DC. It has a 90hp Merc. The guy that had the boat before me had a 13 1/4 inch, 17 pitch prop on the boat. The boat RPM is way to high. When I trim the boat where it is supose to be, I am in the 6200 RPM range. I did try a 12 inch 23 pitch. It did get better, but It still over revs the motor when I get it trimmed to max speed. I am now in the upper 5000 RPM, Like 5800 RPM. I thought if someone had the same boat or can tell me what direction to go in so I do not spend any extra money on a prop that is wrong. I would like to see around 5200 RPM when trimmed for max speed.<br /><br /> Stalker 170

 

[roscoe]

Re: Merc 90HP

5200 rpm is a bit low, really nothing wrong with 5500-5800.<br />That should be easy on that engine.<br />And when you back the throttle down a little, it will save you some gas.