2003 j90 plstc wide open throttle and rpm question

[BenP]

so it looks like the wot range for my motor is 4500 to 5500 based on a few websites, how do i find the true WOT range without the owners manual. my manual jack plate seems to have the motor raised some , ( i bought this boat from a guy that ran flats and bays) I have it on north taxes lakes now and dont need it to be high up on the jack plate. I am wondering if I lower the motor on the jack plate will i get more or less speed. I had it lower an inch last week and currently I am getting 5200 rpms and about 34 mps with myself and no one else on the boat, I think that I was getting more rpms before I lowered it that inch but the speed seems ot be about the same. it is a small motor for my boat. I do not need to go fast but at wide open throttle it seems like i hit a wall where the motor wants to go faster but cant when I am trimmed all the way up. basically i dont get much more speed between 4700 and 5200 rpms. not a big deal since i get on plane pretty good , I just dont want to hurt the motor. any thoughts on if i should lower it or should i just keep it where it is and trim it down a bit and run around 4500 to 4800. thanks in advance and sorry if this confuses yall lol

 

[ondarvr]

Lowering the motor will normally drop your speed and RPM's.

​Having the motor in the high 4000 RPM range at WOT is not good, it needs to be closer to the mid 5's, I didn't look up the recommended RPMs, but none have them that low, and the high end is better for long engine life.

Having the motor lower can mean using a lower pitched prop to get the RPM's back up into the correct range.

 

[BenP]

the charts I have seen have WOT range at 4500 to 5500 . If I am at 5200 at WOT am I messing anything up? I currently have a 15 pitch prop I believe

 

[ondarvr]

I may have misread what you said, if it reaches 5,200 in the current setting, you're probably OK, but if the way you plan to run it doesn't reach those RPMs at WOT then you should run a lower pitch prop.