115 Yamaha correct prop size.

[Shwangman]

I have a 115 Yamaha on a on a 1700 Lund Pro Angler with a 12-5/8 x 21 prop and I was looking at maybe purchasing a Stainless Steel prop but in looking around I can't seem to find one in that size and i was wondering if anyone would know if I can go larger or smaller on either dia or pitch. If anyone could help me out that would be great!!

Thanks

Ken

[Down Deep]

Call Soderbloom's Props and they can tell you what you need. I did and they recommended and provided a SS prop that was the perfect prop for my boat.

[Northlander]

Do a search on Yamaha 115 props selection. It been talked about a lot on here. I run a 17 stainless now and tried a 15 stainless. 15's are working for some guys and some guys a 17 is working better.

Like DD says call Jay Soderbloom at 218-644-3392 and tel him what your looking for. The prop you have now seems way too big to me.

If you cant get him on the phone check out www.soderbloom.com and leave him a e-mail and he will get back to ya asap.

[Scott K]

My 115 has a 17 inch on it.

[Shwangman]

Thanks guys so what I getting from the emails is that the prop that came with the boat is why to big so the smaller the number the bigger the prop size ? The guy i purchased it from got the boat from a local twin city marine dealer and he has a spare, brand new one to go with so, I need to be calling or looking up a 17 pitch until/ ?

Thanks guys, great help as always.

KEN

[delcecchi]

The number like 15 or 17 or 21 is the "pitch" or how far one revolution of the prop would ideally propel the boat. The goal is to select a pitch that will allow the motor to get to its rated RPM when running wide open.

A smaller pitch will increase the motor RPM. From the comments, you are probably not getting to the correct RPM with your 21 pitch prop. I would bet you are seeing more like 4500-5000 at Wide Open Throttle. The motor is rated for 5000-6000 RPM so you want to be in the upper part of that range.

I hope that clarifies rather than confuses

[marine_man]

Before I would think about buying a different prop I would run the boat / motor and see where your RPM's are at when you're at Wide Open Throttle, and trimmed out.

Post that and we'll be able to give you a better educated guess.

marine_man

[dkf]

A 16p or 17p stainless should be close to perfect. Aluminum props are less aggressive than stainless props thus the extra pitch. My boat came with a 21 pitch however a 17p-19p stainless is whats needed for my combo depending on weight.