2008 Targa v175 low top speed?

[CA Dave]

Hi All,
New to the forum here. I recently purchased a 2008 Tracker Targa V175 with the Mercury 115HP fourstroke motor. The boat is in almost new condition and was stored and unused in a garage for at least the last eight years. The previous owner had the motor serviced last June and had the prop replaced as the original had some minor wear or damage.
I've taken the boat out a few times now and have run plenty of fresh gas through the motor and it seems to run fine. My problem is the boat top speed is maybe 29-31mph max by the GPS. That's trimmed out on flat calm water, just myself in the boat, no gear, live wells dry and empty and maybe a half tank of gas. I'm not a speed nut, I was just under the thinking the boat should run faster and max out in the 40mph range with the 115HP motor.
I checked the new prop that is installed. It's a Quick Silver QA2038X 19P. Max speed with this prop when trimmed out is about 31mph at 6100rpm. The WOT range per the mercury 115hp fourstoke manual is 5800-6200rpm. Max speed after accelerating out of the hole without trim is about 25-26mph at 5800rpm. So after experimenting a little, I'm thinking I don't have the right prop for this boat and motor combination, maybe its over propped.
Does anyone out here have experience with a Targa V175 with the 115HP fourstoke and can let me know what performance I should expect from the boat? If my thinking is right about the prop, any suggestions of the best prop for this boat and motor combination?
I am primarily planning to use the boat for bass fishing on the California Delta. Any comments or suggestions would be greatly appreciated.
Thanks,
Dave in CA

[Extremeboating]

I fish out of the CA Delta as well. Welcome to the forum. What part of the Delta do you launch out of?

Out of curiosity, what hole is your motor placed on? Is the prop stainless or aluminum? The RPM sounds correct actually based on the spec you gave. It's better to be on the hot side than the lower side of the RPM band. I would think you should be able to pull a decent amount more out of this engine as well, but it would help to know the specs of the boat like dry weight and such as I know those deep V Targa Trackers tend to be considerably heavy.

[CA Dave]

Extrremeboating - Thanks for the fast reply. Boat specs that I found on the internet (not much info on the 2008 Targa V175 to be found), state the boat weight at 1375lbs, I assume not including the motor, not 100% sure that is correct. Length 17'4", the spec I saw says the fuel tank is 30 gallons, but I think its closer to 20 gallons based on the gas gauge and the amount I put in when refueling. The QuickSilver prop is aluminum, 3 blade. Not sure what hole the motor is placed on, I'll have to go check it.
As for the Delta, I usually launch out of Korth's Marina or sometimes B&W on the Mokelumne.

[Extremeboating]

Extrremeboating - Thanks for the fast reply. Boat specs that I found on the internet (not much info on the 2008 Targa V175 to be found), state the boat weight at 1375lbs, I assume not including the motor, not 100% sure that is correct. Length 17'4", the spec I saw says the fuel tank is 30 gallons, but I think its closer to 20 gallons based on the gas gauge and the amount I put in when refueling. The QuickSilver prop is aluminum, 3 blade. Not sure what hole the motor is placed on, I'll have to go check it.
As for the Delta, I usually launch out of Korth's Marina or sometimes B&W on the Mokelumne.

That prop should not be an aluminum on the larger motor. It should be stainless. You also may want to consider a 4 blade, as those come standard on the new 115's and provide the most grip on the water which is good for turning in your case. The next thing I need to know is what hole is the engine mounted on, on the transom. If you can take a picture of it and post it that would be helpful. It sounds like the boat weighs a solid 1500+ lbs based on what you are saying and the specs I can pull from the V175 on the Tracker site on their modern V models. I think you may be 21 gallons on the tank which sounds correct.

Huh. I've never been to that side of the Delta. I'd have to look it up. I take it you live San Jose?

[Slabhunter]

I have a 2006 Targa 175 with a 115 HP Optimax and I’m sure the aluminum prop that came on it and 41 mph by gps is the best I’ve ever gotten.

[xi0n6]

I have the same boat and the same issue. I've bought multiple prop to test and was a big mistake. I finally got vessel view mobile and it solved everything. My rpm from my tach was reading wrong. I figured my actual rpm and entered it in the mercury prop selector and got my boat up to speed. I could barely hit 30mph on a nice calm day by myself with the prop it came with(13x19p 3blade). I Switched to 13.5x15p 4 blade quicksilver nemesis and my boat jumps out of the water and top speed of 38mhp @5800rpm. I'm going to try 13.8x13p nemesis to see if its better.

[bassfisher444]

That is a heavy boat and there is a reason it is rated for a 150, that boat is underpowered with a 115 on it which is why you aren't getting good performance out of it.