Better Prop for Mercury 25 HP 4 stroke with Tracker Pro Team 175 ?

[Huskybass]

I have a 2006 Tracker Pro Team 175 with a 2006 25 HP Mercury 4 stroke. The boat is 17'6". Thats the largest motor I can use on a local favorite body of water. I have a 24V 70 lb thrust trolling motor, thus there are 2 trolling motor batteries and a cranking battery in the stern. My prop is 9.75" diameter but I am having a hard time reading the pitch, I belive it is 9.5 though. It has a Mercury model #896892A40. It is aluminum and shows normal signs of use for its age.

I do all I can to keep the weight in the boat at a minimum, and with just me and a light amount of fishing gear I can get the boat up to 23.4 mph on the GPS at about 5600 rpms. I never fill the 21 gallon gas tank more than half full and rarely use the livewell. With another 200 pound guy with limited gear I can still get the boat up to about 19 mph at 5000 or so rpms. If I have a larger passenger with me and/or they bring more gear, the boat really struggles to get over 15 or 16 mph.

I am hoping that a prop change/upgrade might help to get the rpms up around 5600 and roughly 20 mph fully loaded. A friend has the same boat with a 2005 Bigfoot Mercury 25 and an 11" x 10 prop. His boat handles the extra weight better than mine does.

My limited research suggests that changing to a 10" x 8" prop may help. I am willing to spend the $ for a better prop (stainless? 4 blade? etc.) if it will help. Obviously, my boat will never be fast, but 20 mph is much more acceptable than 15 mph if I can find a way to do it.

Thanks in advance for any and all replies/suggestions.

Husky

 

[steelespike]

Re: Better Prop for Mercury 25 HP 4 stroke with Tracker Pro Team 175 ?

I think your motor is doing admirably well considering all those batteries in the stern.Have you tried trimming in with a load?You could try raising the motor on the transom by adding 1/4" sticks to the top of the transom.Or perhaps you can simply adjust the mount.antivent(cavitation) plate even with the bottom is considered a starting point.Just be sure it pumps water.
Is there anyway you can move the batteries at least to the middle section of the boat? There are I think 3 smaller props listed here.I believe 1" decrease will net ABOUT 400 rpm.I think there was a 9, 8 3/10 and 8 listed.
Of course you'll have to watch your rpm when lightly loaded.
A bare bones 17 or 18 ft will do really well with a load. My 18 ft Crestliner
with an old Gale 25 planed easily with 6 adults and 2 children.Probably 1200
lbs with the little gear we carried.And I didn't mess with props back then.Didn't have a flat floor but had room for 4 to fish and one was 325lbs.