Prop

I know next to nothing about props other than grinding over the tops of wingdams can be tough on then. Where’s the best place to purchase or shop for a spare (inexpensive) prop on the internet? I don’t even really know how to tell what I need… My motor is a 1999 Merc 4 stroke 50 HP tiller. Any guidance would be appreciated. Thanks, Tut

ebay or craig’slist you can find plenty of cheap back up props, new props tend to be cheaper on those sites too.

You need to look at the numbers on your current prop. There will be a series of numbers followed buy a 2 digit number and a “P”. (The “P” stands for pitch.) That 2 digit number will be 11, 12, 13 or 14 for that motor. In other words you are running some where in the 11 to 14 pitch range. If you were generally satisfied with the current props performance, stay with the same pitch.

The other number you need to know is “Diameter”. The diameter for your prop will be 10 ½ (Ten and one half or 10.5) That number will not change. You cannot go bigger or smaller.

So, when you go shopping you will be looking for a 10.5 x 12p prop assuming you find that the pitch number on your current prop is 12. (And 12 is a very common pitch for that motor.)

If you feel that your current prop should be turning more RPM’s, drop the pitch one number. If you feel that the prop is spinning to fast, go up one number. Again, if you felt the motor ran well, go with the same pitch. That goes for both stainless and aluminum in that 50hp range.

I have found that the Cabelas store brand props perform well and would buy another if I needed to.

Good Luck,

-J.

Jon, Thanks, that helps a bunch. I like to troll with this motor, but I wish I could run my motor at a higher rpm without increasing my speed. If I understand your explanation correctly, speed is a product of rpm and pitch. A higher pitched prop will increase my boat speed at the same rpm and a lower pitch prop will reduce my forward speed at the same rpm??? Therefore, if I want to keep my speed constant and increase my rpm’s I should consider reducing my prop pitch by one number. I could care less about top end speed, because I rarely travel more than ten miles in a day’s time. Thanks again for the information and please let me know if I got it right. Tut

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A higher pitched prop will increase my boat speed at the same rpm and a lower pitch prop will reduce my forward speed at the same rpm???

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You understand it correctly.

-J.

Thanks.