Aluminum 4-Blade Prop

I am running a 2019 Lund 1775 Adventure, with a 115 Pro XS (6300 max RPM). I bought it with an aluminum 4 blade 12.5 X 19p. I was running about 43GPS @ 5400rpm, and an amazing hole shot. I bought a 3 blade 13 X 17p and put it on my boat. The 3-blade brought my RPMs up to 6200, but my hole shot turned to garbage, and I didn’t gain anything on the top end. I am thinking about switching to a Stainless 4-blade 12.5 X 19p (same as my original prop, but stainless). Will I gain any top end or RPM over the original 5400 that I was getting on the aluminum 4-blade? I was happy with the performance of the 4-blade, but would like a little more top end.

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You are spending a lot of money on stainless for a few MPH. You are not going to get the holeshot and more MPH. If you want top-end get a 21 3 blade. Also, look up your manufactures RPM for a motor. It should be running at specific RPM wide open and it is not maxed. You can over-rev motor if not careful with lower pitch prop. Four blades take more power so you loose RPM. I have a prop for tubing and skiing and then speed. Easy to switch out.

You are a little at cross purposes. 4 blades are meant specifically for hole shot and handling. If it was me and I wanted both, 4 blade 17 pitch or even 15 pitch to get your rpm up.

At the end of the day, even the perfect prop will only get you about an extra 3 mph.

You’re really lugging the motor with that 19p 4 blade (900rpms under max).

Like Dave said, look into a stainless 17p or even 15p 4 blade for your next prop.

Guessing it will be putting you in the low 40’s and your hole shot should be even better yet! You want those rpms to hit max when you’re trimmed up.

Sorry to say, but your boat isn’t meant to be a speed demon. If you tried a 19p or 21p 3 blade, you might gain a couple more mph, but it will be even doggier yet out of the hole.

Only so much juice to squeeze out of a fruit. I also carry two props, one for holeshot other topend. Amazingly easy to swap those out.

A 115 really won’t benefit much from a stainless prop. The higher HP motors are where they are a big benefit. The aluminum prop will flex much more with a motor 200HP+. That being said you may benefit with a ported stainless prop to give you a better holeshot. I doubt the cost to gains ratio would be in your favor though.

Yep, 43mph is about as good as you’re going to get. Sounds like you have the 19p spitfire in aluminum which is about the best prop for that 115 range on that size of boat. You’re at that point where you’ll either have to give up hole shot for top end, or top end for more hole shot. You might want to test the 17p spitfire. You might get the RPMs up, but I bet you don’t see much difference in top end, maybe even lose 1mph, but could potentially gain 1mph too, but, I’d guess you’ll stay very close to the same, with an even better holeshot and mid range handling.

Mercury has designed the Spitfire x7 4 blade SS prop specifically for there 75 thru 115 4 stroke engines. I’m running an x7 on my Mercury 90 4 stroke and it’s a big improvement over the original prop that came with the boat.