Spitfire Prop Pitch

I’ve got a 2005 2-stroke 50hp Mercury on my Lund Classic 1660 with console. I’ve got the 10.38x13p Black Max on it now and run 5400-5500 rpm WOT. It lumbers out of the hole with the livewell filled and another person in the boat. I feel like the Spitfire would be a good solution and don’t feel spending on an SS prop makes sense for a 50hp outboard.

It sounds like a like for like swap (13p for 13p) is how the spitfire was designed, but conventional wisdom says pitch down from 3 to 4 blades. What do you all think? Is there anywhere that will let you try the 2 pitches?

Not an apples to apples but I went down from a 19P 3 blade to a 17P spitfire on a 90 horse 4stroke Merc on a 1600 pro sport lund. WAY better, had the same sluggish out of the hole issues and way below max rpm (though I still hadn’t learned what properly trimmed out was yet when I switched). She jumps out of the hole now, I pretty much never run wide open since I don’t like burning through a gas tank every day (its an older carborated 4 stroke and a gas hog) so I couldn’t tell you what my WOT rpms are.

I have never tried a 19P spitfire, I did pick up a 15P Michigan wheel 4 blade knock off type prop dirt cheap over the winter I want to tinker with but haven’t yet. Got the 15P moreso to see what effect it may have on my idling speed for trolling on lake Pepin and the price was so cheap even if it does nothing there it’s a better back up than the 3 blade 19P.

I run a trophy sport 4 blade 13 pitch SS prop on my 50 hp 4- stroke merc On my 16 foot Lowe roughneck

I’ve got a 10″ x 13″ Spitfire in stock from my previous boat, but I expect that we live a little too far apart to arrange a test run. I’d give Ricky at https://brainerdprops.com/about/ a call and see if he’d let you try a 12 or 13.

HRG

Based on your numbers, you might just be a victim of not enough HP.

I run a spitfire, I kept the same pitch I had in a three blade. If you are not getting to the max rpms with your current prop,I would drop in pitch.

I’m running within 100 rpms of max at WOT. Did you get a better hole shot? Lose much top end?

I’m happy with the prop when I’m alone, but when I add people it bogs down on takeoff. I’m still getting 31 mph by myself and 29-30 with another person in the boat. I feel like that’s pretty solid for this setup.

I have an Alumacraft Competitor 165 with a 60HP Mercury 4-stroke. I had similar issues and switched from Black Max to Spitfire. The Spitfire feels a lot better and didn’t seem to affect top speed a noticeable amount. I think the Competitor 165 is heavier and wider but I have 10 more HP and I get the same speeds you listed at WOT, I usually cruise about 27-28 though.

I don’t think I changed pitch, I know the Spitfire is 13 and I’m almost positive the Black Max was too but I’ll check tonight and let you know.

Edit: old prop is 13 pitch too, didn’t change for spitfire

Hole shot much better, lost nothing on top end, much better control in big waves.

Don’t pitch down when going to a spitfire. I went from a spitfire to a pitched up 3 blade and lost homeshot and top end. Spitfire was designed to stay the same pitch as your current 3 blade.