2520/Suzuki 300 Performance?

[CaptBeach]

I have a 1989 Parker 2520 MV paired with a 2021 Suzuki 300. Was wondering what others with this combo get performance wise. I am getting 35mph at 2.1mpg @5000rpm with nearly full fuel tank, 5 adults and 2 pre teen boys, two big coolers loaded. Just me on board was 42mph at 2.1mpg(??) @5300 rpm full fuel and empty coolers.

Still fairly new to the boat and still playing with trim and tabs to dial it in. Motor has 275+/- hours on it. I think its pretty close to being propped right as max rpm is 5300.

I think if I trimmed it out exactly and 1/2 or less fuel Inmight hit 44-46mph. But even 42 mph is not bad for a 25 foot pilot house boat.

 

[Mpellet]

I have a 1989 Parker 2520 MV paired with a 2021 Suzuki 300. Was wondering what others with this combo get performance wise. I am getting 35mph at 2.1mpg @5000rpm with nearly full fuel tank, 5 adults and 2 pre teen boys, two big coolers loaded. Just me on board was 42mph at 2.1mpg(??) @5300 rpm full fuel and empty coolers.

Still fairly new to the boat and still playing with trim and tabs to dial it in. Motor has 275+/- hours on it. I think its pretty close to being propped right as max rpm is 5300.

I think if I trimmed it out exactly and 1/2 or less fuel Inmight hit 44-46mph. But even 42 mph is not bad for a 25 foot pilot house boat.

I have 2005 2520SL, notched transom with a 2019 Suzuki DF300APXX. I now have 860 hours on the engine since hung in the Spring of 2019. I am running a Suzuki Watergrip 3 x16x17. Your performance # are approximately 7% better then mine in terms of top speed & fuel economy.

 

[CaptBeach]

Also on a notched transom and I will look and see which prop I am running. Sounds like I am on the right track.

 

[Mpellet]

Also on a notched transom and I will look and see which prop I am running. Sounds like I am on the right track.

Are your performance #s GPS or paddle wheel??

 

[CaptBeach]

GPS, Two Garmin units slaved to two GPS antenea and the Suzuki Smart gauge which I am assuming draws off of NMEA.

 

[CaptBeach]

Also..
Any benefit to swapping it over to a bracket? I want to close in my transom (hate notched transoms in rough water) and add a twin/single hybrid bracket, one large enough for twins but made for a single. Doing paint and tank swap in the fall. Might as well close it in then and be finally done with it.

 

[CaptBeach]

Also..
Any benefit to swapping it over to a bracket? I want to close in my transom (hate notched transoms in rough water) and add a twin/single hybrid bracket, one large enough for twins but made for a single. Doing paint and tank swap in the fall. Might as well close it in then and be finally done with it.

Pic of my prop.

 

[Mpellet]

Pic of my prop.

You performance #s are better then mine so I’m not saying that it’s the wrong propeller for your boat BUT I can say with 100% assurance, that propeller would be too much for my boat and the engine would not make it into the recommended RPM zone at WOT….

 

[warthog5]

Pic of my prop.

You have the Wrong Prop. It's also evident by your RPM numbers.. Your making that engine labor.

The prop you have works well on a 23ftr with a 8.5beam boat.... But not on a 25ftr with a 9.5 beam boat.

You need the Suzuki 3X16X17

 

[CaptBeach]

Ok...I will bite.

Going to the prop you recommend what would I expect to happen to my performance? 42mph on a 9.5' beamed 25' boat aint bad. Would I pick up speed? Better fuel burn?

 

[warthog5]

Our boat was a '95 2530... Med V

42MPH Top end was White Knuckle.... You didn't want to push that hull that fast.

4200RPM would = 25MPH..... 2.0MPG in the Gulf and 2.5MPG in the Bay.

The boat will get out of the hole Much better... It will Push that Hull thru the hard current and waves at the inlet/pass.

Very surprised to see you even having a 18.5 pitch... As the 17 pitch has been the Go to for these boats.

That engine is supposed to operate 5700 to 6300 RPM .https://www.suzukimarine.com/outboard/225-300hp/df300ap/

 

[Mpellet]

Ok...I will bite.

Going to the prop you recommend what would I expect to happen to my performance? 42mph on a 9.5' beamed 25' boat aint bad. Would I pick up speed? Better fuel burn?

I don’t typically tell other people what they should do with their boats or what to buy, so all of the following would pertain to my 2520, which is 19 years old, has bottom paint, several anchors with a lot of chain & other gear that’s always on board before I load coolers & ice . Coolers for an offshore trip will be 2 x 165qts filled with ice and another couple of soft sides for food & drink.

On my boat that 18.5 pitch would have my Suzuki DF300APXX lugged big time and the engine would be slow to get the boat on plane and there wouldn’t be any chance that I could get the engine close to recommended WOT RPM with the boat loaded for a typical offshore trip. When operating in rolling seas, requiring changes in power to climb the boat out of a hole performance would be unnecessarily sluggish with the 18.5 propeller.

I would think that on the rare occasion when operating with under 1/2 a tank of fuel , just myself, running in calm water with the 18.5, the top speed would be faster then with the 17” but those are not realistic operating parameters for me.

I have an old 2001 Chevrolet SS Camaro with a 6 speed standard transmission, 5th gear is a do all gear on the highway. Car accelerates rapidly and if desired you can run well over a 100mph without worrying about the red line on the tach, 6th gear when you can use it will yield 100mph at 2200RPMs and 25mpg (not exaggerating). The car accelerates like a slug in 6th gear but when the road is open and you’ve got distance to cover it works.

Our outboards don’t provide the ability to change pitch so we’re faced with compromise and on MY boat running an 18.5 pitch would be like trying to drive my Camaro around in 6th gear all the time, whereas the 17 pitch is 5th gear and at least 80% of the time is the optimum gear/pitch.

If I had an 18.5 on MY boat, I’d replace it with a 17 and keep the 18.5 as an emergency spare. I also think my engine would thank me in the long run for not running around over propped which could shorten the operational life of the lower unit and or the powerhead….