How to get more top end out of 25 HP Merc

[Paul Welc]

Hi all,



In 2005 I purchased a Bass Tracker with a 25 HP Merc Bigfoot 4-stroke (most of the lakes in my area have a 25 HP limit). Top speed with 2 people is about 19 MPH, boat planes out at about 17-18 MPH. Any good way to give me 2 or 3 MPH more on top end speed. New prop with different pitch and diameter? Hydro foil?

 

[Bruce Freeman]

Paul, what are the WOT (wide open throttle) rpms? The foil would only help get on plane not MPH..



BF

 

[Paul Welc]

Bruce the WOT rpms are around 5800 - 5900 rpms.

Most times I'm on plane (90%,)but going up current against wind, I kind of half plane half plow sometimes. I think if I could get a couple more mph on top end I would be on plane 100% of time.

 

[RH gone]

In this case, I think a foil is appropriate. I have a 2002 PT175 w/40 merc. One of the first things added was "The Angler" by Cobra Marine. Fully loaded, three batts, full tank and two guys, it steps up on plane at about the same time the speedo starts working (at or around 10 mph).

 

[Rob LaMoy]

You're getting all you can really expect from a 25 hp. Not a lot of ponies there to play with for performance. Changing props might have an adverse affect because of the smaller size of your engine. Whenever you're dissappointed with mph just think about the gas you're saving, take a ride with a 225 HP and fill that tank, then the 25 hp won't seem so bad at all.

 

[fatrap]

The only thing I can suggest is to lighten the load. Only take whats necessary. If you have your boat loaded "Neeley Style" all the added weight will make a big difference.

fatap

 

[Rich D]

I have been thinking of getting a foil for my 25hp to help with plane. Unfortunately the only way to lighten the load in my boat is if I stay on the dock!



Rich D

 

[fatrap]

Like Rob said a 25 doesn't give much options on preformance upgrades. The only other thing I can suggest is balance the load as best as possible so you can get a little bow lift. Might help

fatrap

 

[TOMMY RICH]

Hidden Supercharger?:lol:

 

[Paul Welc]

Thanks guys. I have been running with a half tank of gas to lighten the load. I only use the 25 HP motor to get from spot to spot so no big deal on small lakes, if I could only squeeze about 2 mph it would be great. The funny thing when I bought the boat the mechanic stated we keep the stock prop on the boat but if you want it changed out bring it back, so I wasn't sure if that was a hint? I have read on the forum other people with a 25 HP 4-stroke are running at about 22-23 MPH. Didn't know if there was an easy way to do this (prop change or hydra-foil or both).

Tee you have an extra supercharger laying around, LOL. It did cross my mind when I purchased the boat to get a 40 HP and put 25 HP stickers on it but my luck I would be on the front page of the DNR magazine!

 

[Steve Rizza]

Power trim ???? If not, it would be about the best way to spend your money.





Steve

 

[Paul Welc]

Steve, I have the power trim. My boat has a lot of torque out of the hole shot, it just falls a little short on top end

 

[Marty Klein]

:lol::lol: 25 HP--lot's of torque--hole shot--:lol::lol:

 

[Paul Welc]

Thanks Marty, LOL

 

[Bill Wright]

Paul, nice looking boat. I had the 165 with a 25 and tried everything. Dont waste your money. Just enjoy it. It is a very good motor.

 

[TOMMY RICH]

Those lil' 25's are bulletproof

 

[Paul Welc]

Once again, thanks everyone. I love the boat. I really only have trouble once in a while when I'm on the river going upstream (maybe 2 or 3 times a year). Most of the lakes I fish don't have current so the boat is fine on them. Looks like a great weekend to go fishing!!!!

 

[Steve Rizza]

Like the others said, just enjoy what you have. If you found 2-3 more mph, then you would just want 4-5 more. I understand though, it's a guy thing.





Steve

 

[pete hanford2]

You wont get anymore out the 25.I have a 25 on my pro 17.You can change the bar thats goes thru to lift the motor like to use it for shallow water.thats what i do.someday i will get a bigger motor for it

 

[William Schram]

Put a 0 behind the 5

 

[XMYTRUCK XMYTRUCK]

I have a PT165 I fastest I have every gone on my boat us 27-28 that was just me a clam day , and a 1/4 tank of gas.. With two guys I average about 23-24, but keep in mind pt 165 is 15'10 and 52 inch wide alot less foot print in the water... My prop is 11 pitch merc part number# 4885632A40



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