1860 w/ 90 Mercury Tiller prop suggestions

[Spillwayskeeter]

Wondering what’s a good starting point on props. Running a 3 blade 17p rn and it will only do 36-38 with 2 people. Boat has a 60” floor and a 48” running pad. 26 gal fuel tank under front deck, 24v trolling motor, 2 lithium deep cycles under deck. Polling platform on back, atlas jackplate. Seems to only run good without hopping with the jackplate almost all the way down.

[RyanJ]

I doubt you will see much more out of it. I have an Alumacraft 1860 with 90 4 stroke console. Same fuel tank but in rear. 2 27 batts in front deck with charger. Ultrex. 6' manual jackplate all the way down. 2 people and gear I get about what you get with either a 3 or 4 blade sst prop.

[GeauxTide]

You didn't state if prop was SS. 36-38 is pretty good with 208# of fuel, two batts, and a TM up front. If you've got to put the JP almost down, then ditch it. I fooled with several props until I tried the Spitfire X7. Magic.

[Spillwayskeeter]

You didn't state if prop was SS. 36-38 is pretty good with 208# of fuel, two batts, and a TM up front. If you've got to put the JP almost down, then ditch it. I fooled with several props until I tried the Spitfire X7. Magic.

Prop is SS. It runs best top end with the jackplate low, but in shallow water I can jack it up and it will keep 10-15 psi. Im going to go to my local prop guy next week when I get off work and see if he has a spitfire I can try or what he thinks. Thanks for the insight

[Spillwayskeeter]

I doubt you will see much more out of it. I have an Alumacraft 1860 with 90 4 stroke console. Same fuel tank but in rear. 2 27 batts in front deck with charger. Ultrex. 6' manual jackplate all the way down. 2 people and gear I get about what you get with either a 3 or 4 blade sst prop.

Thanks for the input man. The boat looks crazy over powered. Was originally ran with a 40 GTR mud motor and the guy was getting 32-33. So I figured it would gain a lot more with 50 more HP

[tcesni]

Wondering what’s a good starting point on props. Running a 3 blade 17p rn and it will only do 36-38 with 2 people. Boat has a 60” floor and a 48” running pad. 26 gal fuel tank under front deck, 24v trolling motor, 2 lithium deep cycles under deck. Polling platform on back, atlas jackplate. Seems to only run good without hopping with the jackplate almost all the way down.

What are your WOT rpm’s?

[Spillwayskeeter]

What are your WOT rpm’s?

Depends on load and jackplate height but 5600 usually when running WOT. I can lift the jackplate and gain rpm but speed stays the same

[RyanJ]

I forgot to add I am now running the spitfire 4 blade stainless prop. Really good hole shot and nice mid range with some lift. I hit about 5500 to 5600 rpms wide open. There is not much room to play around and gain with these style hulls. I would focus on hole shot and midrange.

[Spillwayskeeter]

I forgot to add I am now running the spitfire 4 blade stainless prop. Really good hole shot and nice mid range with some lift. I hit about 5500 to 5600 rpms wide open. There is not much room to play around and gain with these style hulls. I would focus on hole shot and midrange.

What pitch are you running?

[RyanJ]

What pitch are you running?

13X17 X7 spitfire with vent holes plugged.

[GeauxTide]

The thing to remember about the Spitfire - it will really lift the stern, giving you more leverage to lift the front, although your front loading won't allow for much.

[FrancoCialone]

The proper prop pitch will run your motor at the upper end of the rev range at wot, and give you good holeshot with a normal load. Holeshot and midrange torque are more important than top speed. Its hard to get all 3 with an aluminum tiller boat. Your pad to prop shaft distance is important as well, you prop guy should know all this.