Re: Force 150 performance
Deer, I would find out what the rated maximum RPM is for that motor and prop it with a high performance Stainless prop to reach the Max RPM or even 100 or 200 over the limit should be fine, without hurting the engine what so ever. <br /><br />I used to be extremely paranoid about "Max RPM" And many mechanics that I spoke to always said to do the max or 1-200 below. These motors are built so strong internally. If I were to describe a engine that had an Aluminum block, solid steel crank, and roller bearings throughout, you would think I would be describing a raceing engine!! Oh, I could could go on and on, but believe me, Marine service is the toughest challenge for ANY engine, and the 2-stroke engine puts out more horsepower per pound and is more durable than any engine made, and I mean any.<br /><br />Can you tell I like 2-strokes?<br /><br />I have owned 5 and have re-built 2. I currently have a Evinrude V-8 300hp which is a wonderful motor! Circa 1989 and never a problem with it. In fact the 2 that I re-built I purchased that way so I could learn from them, a 150 merc and 225 evinrude. Please learn everything you can about good maintainence, bad maint. is what takes these motors down.<br /><br />Ok so I am rambling on here quite a bit. I am not sure what you want for performance. I can tell you a story about my first boat a 16 foot deep V with a 90hp Evinrude. Great little fishing boat And it would struggle pulling a 200 lb skier on a slalom ski using a factory 17 pitch aluminum. A friend owned a 15 pitch OMC SST stainless prop, so I tried it, On the first pull it ripped the handle right out of my brothers hand, it wasnt even the same boat! I was so impressed. The motor reved higher which put me in the upper end of my rating but maintained the same top speed and all around performance was much improved. Now you will lose a gas mileage by running a smaller prop at WOT, But I personally dont lose sleep over stuff like that.<br /><br />Now back to the story. After I returned the Stainless prop, I went out and bought a 15 pitch ALUMINUM prop thinking that the performance increase that I had gained was due to the fact I had gone from 17 to 15 pitch and not so much because it was stainless. Boy was I ever dissapointed! I could feel the differnce, it was definetly more sluggish. Just a note: all of the above props were new conditon OMC propellers so I felt I had some good comparisons.<br /><br />Just remember that the RPM range rating from your manufacturer is the range that your motor creates its rated horsepower. It doesnt mean that you cant go over a little. It actually saddens me to see so many boat owners running in the lower end of the recomended range with a aluminum propeller thinking somehow they are being "safe and good" to thier motors and never really finding out what boat is truly capable of.<br /><br />Ok, now I am going to explain why aluminum isnt the way to go if you want your best performance. Stainless blades can be made thinner that aluminum, its that simple. But I will ramble some more and probably complicate it! Ever see a drag racer do a burn out to heat up the rubber on his tires?<br /><br />This creates better traction and hence effiency as he runs the 1/4 mile race. Well that little propeller back thier represents the equivelant of two rear tires on a car! The leading edges of your propeller should have NO dings, nicks, or dents as it Slices the water. If you added up the total length of the leading edges of your prop you may have a length of 24" x 1/6" Thick. Now do you realize just how important this dimension is? What if it could be made 1/32" Thick instead of 1/16"? That is a 50% improvement on a very crucial part of your prop. Think of these 3 blades literally Bashing through the water. Would you rather bash the water with (for example) with the palm of your hand? or the edge of your hand?<br />Get the picture?<br /><br />Now Deer, you seem to be pretty happy with your set-up and thats just fine! (most of us never are) But if ya want to surprise a merc or two, or just have the pleasure of knowing that you will outperform other boats in your class you would be advised to consult with a professional prop guy, He will know what would work best for the performance that you would like to achieve. I know that my old OMC prop was just a middle of the road stainless prop painted black from the factory, but yielded impressive results. I have heard alot about "Rich Boger" you can find him on the web, I think I am going to send him my prop for fine tuning. If I get a chance I will let ya know how it went.<br /><br />Well I better get goin, my fingers are sore!<br />Hope things work out well for you
Mike
