I am lookiing at getting a different prop. First question is what is your WOT. I don't understand how this is accomplished. I have a Mery opti 115. I get it on pad and then trim till my tach shows 5500-5800 rpm's (depending on water conditions). Thats all I know. Is there more to it?

WOT = Wide Open Throttle.

Just like says, your throttle in the fully open position.

Is this what you are asking for???

Scott

I know what the letters stand for (WOT) but I can have the throttle wide open and engine trimmed down and be at 2000 rpm or trim so far up I can hit 6000 rpm +. Here is what I am trying to understand.
http://boatpropellers.iboats.com/propeller-tutorials/rpm/?cart_id=450570872

WOT is just that, having the throttle all the way to the stops. But, your prop and engine setup ultimately determine your speed and performance. The RPM range you are currently running seems in line with the motor. But, at those RPM's, does the boat act like you would like it to? Does it lift well enough, does the speed suit you, etc.? Even fuel economy is a factor. To change those characteristics, you'll have to change props. If you're currently spinning a three blade, look at a four blade for more lift and stability. Need more speed, look at bigger pitch 3 blade. Then factor in engine height and setback, if you have a jack plate. There are a ton of variables and only you know how you would like your boat to perform. On a different note, it appears you are a service person? If so, thank you for your efforts on behalf of me and my country men!

need this info: wot rpm's, prop and pitch of prop, pad to prop setting, boat model, this will let us tell you what is going on.

the fact that you can trim that many rpm's difference tells me you need to maybe raise the engine some, 4-600 rpm should be normal imo from no trim to full trim. it will depend on water conditions and weather that day too.

If you can hit 6000+ then you need more Prop. You do not want to OVERTRIM your motor to exceed your RPM LIMIT. The motor will stop trimming up and at that point you want to adjust your prop size and motor height to RPM's approx 5900 (for a safety factor) in the Winter/Colder temps.(As a general rule of thumb.) In the Summer the RPM will drop. Also, if you trim it up too high and only have cable steering then the Steering wheel torque will be very significant. Prop selection is a "specialty" in itself. TYPICALLY Lower pitch will help hole shot but decrease top speed, and increase TOP WOT RPM's. Higher Pitch will slow hole shot AND decrease RPM's but can increase top speed. You have to find a "happy medium" between hole shot, top speed, control, Motor Height vs safe water pressure for cooling, and RPM Limits. Check with the Guys on Bass Boat Central (bbcboards.net) for your boat. They have a lot more discussion about the technical issues.

To answer your question.....WOT is the absolute best speed/rpm you can get on a given setup.

Shoot, I thought it stood for..."Wide Open Tank"..
as in Empty

pedal to the metal

Thank you guys for your help, except the exhaust sniffer. But I think I'll need a talk session on this one.

A little advise....WOT is a good thing, boat is trimmed right, the water pressure is in the mfg range, the rpm's are in the mfg range, boat is traveling at it's greatest speed...basically all is well...BUT, if any of the mentioned variables are out of whack then something is wrong and you could blow up the motor !!!...call the mfg and ask them what your WOT water pressure and rpm's should be...then when running at WOT keep an eye on these gauges as we'll watch the GPS as you trim up you will watch your rpm's go up and your speed increase, you will reach a point of greatest speed then it will start to fall off you then know to trim down to the sweet spot...if your rpm's race above the recommended range while at WOT then you can increase the pitch of the propellor an inch or so till your running in the middle to the high end of the range, you never want to over rev or bog the motor down as this is bad for the motor...always watch the water pressure...as you figure it out you will notice other factors will affect the formula like temp of air or water and amount of load...just remember the two most important factors being water pressure and rpm...I hope this helps a little...good luck !

Get this info and call steves custom props he can answer all the questions you have and fix you up with what you need to buy if you need to change props. He will also know what motor height will be best.

http://www.mercuryracing.com/propellers/propslipcalculator.php

Run the numbers and let us know what your "prop slip" is.