90 etec question

[Kyle Posterick]

Fellas,

A buddy of mine just took delivery of an alumacraft 1860 all weld with a 90 etec. Decided (against my advice) to purchase a 19 pitch Powertech 3 blade stainless right off the bat.

We went out to adjust the jack plate and do some test runs and look for best overall performance. From factory we ended up moving the jack up about 3 inches (cav plate runs close to 4.5-5 inches above transom), hole shot is good and the motor spins about 5k at WOT. Top end is right at 39-40 with two guys and a full tank of fuel. 40-41 with just one guy.

MY question centers around the RPM band of the Etec. No matter how high we lifted the motor (we went up the full adjustment, 4.5 inches and were blowing out on take off) we couldnt get the RPM's to go over about 5050, Ive only worked with smaller HP motors and aluminum props, there I normally see a general trend toward higher RPM until you cant get the prop to bite. On this motor and prop combo the motor would spin up to 4200 or so and then trim would let it pick up another 800 or so, but nothing would get it up into the magical 53-5500 rpm band. Is this just to much prop? Does an etec limit RPM during the initial break in period?

A 17 pitch would work alot better. The selling dealer should have propped it out correctly.

[RickOnt]

Kyle

Your Bud needs to get the RPM up for sure!

A 90 on the 1860 is minimal.

He will likely need a 15 pitch.

I am using a 4 blade stainless Roque and am very pleased.


Rick

[eagle19eye]

Im pretty sure the RPM is not limited on break in. Just the oil ratio which is preset for "double oiling" on his 90 for two hours on initial break in.. Sounds like the prop is incorrect.

[I Fish Therefore I Am]

http://www.etecownersgroup.com/

This is where the techs hang out. Post your question there.

Bud

[ziemann]

A reputable prop shop will allow you to try props until you find the one that best meets your needs. You are 100% correct that you need to get the RPM's up- I suspect as well that you will end up with a 15P as well.

[Kyle Posterick]

That particular motor has a max rpm of 5500, we talked it over and he is happy as it sits, He may go get a 18 aluminum to see what It will do.

[Thunderbucket]

The 90 etec optimum rpm is 5200 WOT