[Bullet Head]

I need some help. I was told that my 23 pitch prop on my 225 Yamaha is to small. I'm turning to many rpm's. It was suggested to me to try a 25 pitch Tempest with a Yamaha insert. I was told to try Carl at Props Plus. Any help would be greatly appreaciated. Thanks. Bullet Head

 

[Delw]

He's right if at wide open your over your max RPM you need to get a bigger pitch. its roughly 200 rpms per inch(if I remember correctly) novice dave knows the exact formula





Delw

 

[Turtle]

Go for the 25

A 225 Yammie on a typical bass boat should be running a minimum 25" pitch prop, a lot of them run 27". Props will differ from manufacter to manufacter, hence a 25 Yamaha Pro Series will probably have different characteristics as far as hole shot, top speed, etc. than say a Tempest. If your boat is running fairly heavy, lot of equipment or it's a F/S, the 25 ought to do better than the 27 since it will keep your rpm's up so you have a little more tourque and better hole shot. I'm running a 25" Yamaha prop on my 150hp, but I definitely could'nt go higher. Best of luck!

 

[fsh2win]

Im running a pro series 25 on my 150 and would be willing to swap ya out for the afternoon... I am thinkin I might have a little too much and need to drop to a 23. just a suggestion. Let me know.
keith

 

[MultipleMigs]

Prop Formula

Bullethead: I'll try to keep this simple. The prop formula is as follows:

Speed = (RPM x Pitch x Slip Factor)/(Gear Ratio x 1056)

Two characteristics that you must know about your motor are the optimum operating range in terms of RPMs for that particular motor and the Gear Ratio . This is easily found by looking at your engine manual or possibly Yammie's website. In your case, 4500-5500 RPMs and 1.81, respectively. You want to run near the high end of this so you don't tend to 'load' the motor. You can assume the Slip Factor to be equal to approximately .9-.93 for stainless steel props and .87-.9 for aluminum. We'll get to speed in a little bit.

Using the formula above and solving for Pitch results in the following:

Pitch = (Speed x Gear Ratio x 1056) / (RPM x Slip Factor)

Assuming a speed of roughly 68 mph, the pitch required to achieve this w/ your set up would be 25-26 inch. I used a slip factor of .93 in this case. The higher you go in pitch, the faster your set will be at the top end. The lower pitch will give you more lift and quicker planing times, but you sacrifice speed. This is where you have to decide what's important to you. If you need help w/ calculating anything, shoot me a message.

Another prop shop I suggest is Precision Prop. I have had better luck w/ them.

I hope this didn't confuse you!

 

[Guest]

I have a almost new 25 pitch tempest prop for sale. I have a 2001 NItro 288 SPort fish'n Ski and I went to a 5 blade High Five Prop 23 pitch for a better hole shot, but I had to sacrifice speed. This should be the perfect prop for u. Shoot me an email if u are interested.
[email protected]

Tight Lines
J.D.

 

[Guest]

JD is it a mercury prop, and much do you want for it.
JB

 

[Guest]

Yes it is. I just posted in the forsale section.

Thanks,
J.D.

 

[Bullet Head]

Guys, thanks for all the help. I think I'm going to wait till I finish the remodel on the boat so when I get the new prop all have the boat in fishing trim. I went and purchased all the materials for the remodel and weighed everything. With what is coming out of the boat and what is going back in the boat it looks like I'm going to be adding about 60 to 70 pounds. One nice thing about my boat is that most of the weight ( gas tank,batteries, live well) are mid-ship. The boat planes out very quick and easy. I,ve been told by several different marine machanics to make sure the tach is reading correct before I change props. Alot to think about and I'm enjoying every bit of it. Thanks again for all the suggestions.
Mitch