165 cs naviagtor with 90 etec prop questions

I have a month old 165cs navigator with a 90 etec. It just doesn’t seem to have much top end and the bow doesn’t lift out of the water. I know the last few feet will stay in the water, but I get side splash up to the front of the console. I have ran 2 props so far 13.5×15 and 15×17 the first runs about 5500-5600 and the second 5000-5100. Both run from 33-36 mph. The slower with a full tank 23g and 2 people and a 75 lb lab and a few fishing items. I have moved the motor from the dealer 2nd hole to the 3rd and now its on the 1st. Handles much better in corners now! The cavitation plate rides even with the top of the water at wot. It just doesn’t lift! Would a hydrofoil help? Cupped stainless prop? What pitch? 4-blade? I hate to spend a few hundred on props and have the same issue. Maybe its a normal consern, but on Alumacrafts web page the 165cs naviagtor with the yammy is almost all the way out of the water. Ideas welcome!!! By the way I know I was ready to dump this motor earlier last month, but it has been perfect since. A little noiser than a 4 stroke, but that’s the only disadvantage I see.

I looked at the preformance data on the website and it shows it getting 38.8 with a 90 horse, but I can’t tell what kind of motor. I know they usually don’t have them loaded down very much when they do those, but it seems like you should be getting more out of her. I have a 2001 navigator which is what they now call the “classic 165” with a 70 susuki 4 stk and I can get 34 by myself with a full tank (22 gal) and about 33 with 2 people (gps). my dad has a 175 navigator with a 115 and it really has a lot of lift in the bow. Did you talk to the dealer about it?

I have a 2004 alumacraft magnum 165 cs with a 2005 90hp etc.

It goes exactly 41.1 mph in 53 degree temp water running at 5200 rpms with a michigan ballistic ss 3 blade prop 13 7/8 x 17.

Average speed is around 38.8 with full load, 2 230lb guys, full tank gas, full livewell and I have 3 group 29 batteries for a minn kota trolling motor up front of the dash 2 optimas in back for electronics/starting motor.

I am guessing my setup is heavier than yours and my bow lift is extreme. 1/2 trim (on the guage) is wot throttle, trim up on the motor up from that and the bow wants to porpoise.

From the stock 14 x 17 x 3 aluminum prop to SS, I got exactly 3mph more top end. Holeshot on either prop was instant (you actually feel your back press against the seat).

I have 4 extra props, all of which are 19 pitch and above and in each case performance suffered quite a bit.

Hydrofoil will not help, only with holeshot as the hydrofoil runs out of the water at wot.

Are you running SS (stainless steel?)

I would go to a lower pitch so the RPM’s get higher I believe you should be running closer to 6,000. My 60 etec does not take off until the higher RPM’s kick in. I have to trim out a bit to get the RPM increase. Go too far and I get too much lift and porpoising and wheel torque. I am running a 13.25×17 Michigan wheel stainless. I think running 100% gasoline makes it run better, also the cooler water.
Motor seems to be getting better with age although it is only a 2006 put on in March. I put shims on the motor to get the trim in and jacked it up 1 notch as it was mounted all the way down. Not sire the shims helped the hole shot, but did jack the motor back a little.

WOT should be from 4500-5500 rpms.

http://www.evinrude.com/en-US/Engines/Showroom/ProductSpecs.htm?productID=ETEC90

Send me a personal E Mail and I will give you my son’s E Mail address. He has the same boat and a 90HP E-TEC. He is kinda picky and had someone cup his prop. The kid is now happy because it corners much better and the hole shot is quicker. The top end is about the same and for whatever reason a few miles slower then my Crestliner.

I have a Crestliner Fish Hawk with a 90HP E-TEC, and it came with a 19 inch prop. RPM’s were fairly low but within range and it ran fine. The son talked me into trying a 13 7/8 by 17 inch prop and it really didn’t make a lot of differance. Higher RPM’s, but around the same speed (38-41 MPH).

Anyway, the prop guy is in Minnesota, helpful and reasonable.

My bad, your link is incorrect, but I checked it out anyway and you are correct there at 4,500-5,500. Strange, my 60 wot is 5,500-6,000 so I assumed it would be the same for a 90.

I have put a 13 3/8 x 15 pitch michigan stainless 3 blade on it. Bow lift is better not great(just behind driver), handles way better but top speed only 34-37 depending on load, and this gps speed not some bs fishfinder or dash gauge. According to my lowrance x65 the boat goes 49!!! A balistic would probably help but hey its a fishing boat how much $$$$ can I spend on props!! I did have one aluminum 15pitch custom cupped also It’s great for cornering, I mean full trim wot 180 degree turns and no problem JUST HANG ON!!!! Any other suggestions appreciated especially from alumacraft owners, motor is on 2nd hole now. (1 being on top=full down on transom)Raise it again????