2005 Nitro 700 LX Prop

[ZJGardner926]

I purchased a 2005 Nitro 700LX with a 90 HP Mercury last fall. The boat came with the factory 19P aluminum prop. Performance was OK with this prop, but hole shot was lacking. This winter, I made a couple trips to my local boat store talking about stainless props. I ended up getting a Solas Saturn 21P Stainless prop. Hole shot with this prop is great, but I actually lost about 1 mph with top end. I max out at 44 MPH at 5,700 RPMs. I thought the RPMs seemed high, especially since the engine plate says "Max RPM 5500." The guy at the boat shop said this was a 5k-6k RPM engine and this would not hurt anything. Now I don't know what to do. Do I risk damaging my engine at this RPM? Also, how do Solas props compare to name brand props?

[Mike Cork]

typically when switching to a SS prop, one has to go down in pitch to maintain any kind of RPM. By the way you are talking I assume you went up in RPM? What was the RPM on the stainless prop?

Did you do any motor height adjustments at the same time?

[ZJGardner926]

I may have it backwards. I'll have to look at my old aluminum prop when I get home. It may have been a 23P instead of a 19P. Now that you mentioned stepping down, I am almost certain that it was a 23P aluminum. I know my stainless is a 21P. The RPMs did go up by 200-300 at WOT. I am at 5700 RPMs on the stainless prop. I did not make any motor height adjustments. I am interested in setting my motor height correctly. I don't have a jack plate, so I'm trying to figure out how I would move the motor up and down. It is mounted in the center hole position on the transom. I am guessing I would have to unbolt the motor from the transom and raise or lower the motor to the next hole?