Prop help 75 hp 4 stroke mercury

[LandOfRath]

I recently picked up A 2006 Smoker Craft Osprey 16dlx
While getting it running better I noticed it tends to nose up pretty high unless play with the trim to get it to plane out.

Well I managed hit something in a canal and noticed I sheared a few inches off of one of the prop blades, and while shopping around for a replacement I was wondering if there is a better option than what is on there? Currently running a 7734A45P17 Mercury prop

I upgraded from a much heavier boat so its entirely possible I am still adjusting to the characteristics of a different boat.

 

[Texasmark]

Trim definitely is a necessity to find the right combination to support the associated activity. Your new boat, besides being heavier may not have as good of a planing transom area as your old boat. Flat hulls at the transom vs hulls with significant dead rise at the transom plane much easier with less hp. What is your speed and WOT RPMs on the new boat? Old boat?

 

[LandOfRath]

Trim definitely is a necessity to find the right combination to support the associated activity. Your new boat, besides being heavier may not have as good of a planing transom area as your old boat. Flat hulls at the transom vs hulls with significant dead rise at the transom plane much easier with less hp. What is your speed and WOT RPMs on the new boat? Old boat?

New boat is much lighter.. 1500 pounds lighter lol

Sadly I don't know what rpms were running, I think it got up to about 38mph using a cell gps app. It is something I will be paying attention to going forward when I get a new prop. If I really get on it, it gets on plane and handles fine with minor trim adjustments.. But going slower the front end is up pretty high. I am guessing ill stick with what it had and play around with it this season and see if I just figure it out.

I am not sure how fast a 1000 pound boat with a 75 hp mercury should go.

 

[Scott06]

I am not sure how fast a 1000 pound boat with a 75 hp mercury should go.

Off the cuff I would say mid 30s so you are probably pretty good. Key is to prop int the upper end of the recommended wot range

 

[LandOfRath]

well just put on the new prop, if I have time later ill put the boat in the lake and see what the numbers are

 

[QBhoy]

Hi. I’d be quite sure it’s just as a result of a light boat, with a heavy (if the engine is the same age or early 4 stroke) heavy lump on the back

 

[vroom ZOOM]

make sure you are trimming down fully when accelerating from a standstill. If you want more stern lift then go with a 4 blade prop.

 

[LandOfRath]

I'm getting used to it.. WOT at 5500 at 32 knots.. played with it for a out 60 miles of river exploring. Now trying to figure out a different issue.

 

[LandOfRath]

Hi. I’d be quite sure it’s just as a result of a light boat, with a heavy (if the engine is the same age or early 4 stroke) heavy lump on the back

359 pounds which I guess was the lightest available in the 4 stroke class..
so yeah thats a lot of weight for a 1000 pound boat lol