2005 2520SL Notch Transom Re-power

[Big Block]

Debating re-power options. Basically narrowed it down to Yamaha and Suzuki - 300 or 350. I currently have a 2005 F250 which has served admirably with a Rev 4 merc prop. What I really want out of a new motor is something that will push at 20-24 knts at 3500 -4000 RPMs for max economy without lugging. The 250 has always seemed underpowered and bogging. I run mostly outside, and heavily loaded 4+ souls.

I am leaning towards the Yamaha 350hp. Would love 1st hand experience with that motor on a 2520 SL.

Thanks

J

 

[Mpellet]

Debating re-power options. Basically narrowed it down to Yamaha and Suzuki - 300 or 350. I currently have a 2005 F250 which has served admirably with a Rev 4 merc prop. What I really want out of a new motor is something that will push at 20-24 knts at 3500 -4000 RPMs for max economy without lugging. The 250 has always seemed underpowered and bogging. I run mostly outside, and heavily loaded 4+ souls.

I am leaning towards the Yamaha 350hp. Would love 1st hand experience with that motor on a 2520 SL.

Thanks

J

I have the same boat. I hung a 2019 white Suzuki DF300 APXX on it in the Spring of 2019. The “new” engine replaced a 2005 Yamaha F225. I have logged 1308 hours on the “new” engine. It’s been a big upgrade from the F225 in both performance & economy. I’m running a 3 x 16 x 17 Suzuki Water Grip Propeller and am happy with it.

Six seasons in so far, my top end isn’t super fast maybe 35 kts in absolutely perfect conditions with a light load but where the 300 shines is getting the boat on plane, it does so seemingly effortlessly regardless of sea state or how heavy the boat is loaded. I never get that bogged down feeling like I did when the boat was heavy running with the F225 on the transom.

If you’re a DIY, water pump & t-stats are easier to replace on the Suzuki and the other routine maintenance items are about the same as they were on the Yamaha…

 

[warthog5]

20-24 knts at 3500 -4000 RPMs for max economy without lugging.

Your expectations are to High. More like 4400 - 4600 for those speeds.

 

[Mpellet]

Your expectations are to High. More like 4400 - 4600 for those speeds.

Your #s are exactly what I get for cruise speeds and RPMs running the 3 x 16 x 17 Suzuki Water Grip Propeller, which is as much pitch & size as my engine can take. Any more wheel and I would be over propped.

 

[Big Block]

Your expectations are to High. More like 4400 - 4600 for those speeds.

I get 24 at 4400-4600 now with the 250, top is 30-32. That's also why I am leaning 350. Do you know much about the dual prop Zuke?

 

[Big Block]

Your #s are exactly what I get for cruise speeds and RPMs running the 3 x 16 x 17 Suzuki Water Grip Propeller, which is as much pitch & size as my engine can take. Any more wheel and I would be over propped.

What is your top rpm and speed with that prop?

 

[warthog5]

That's also why I am leaning 350. Do you know much about the dual prop Zuke?

One of my friends is shop forman / Super Marine Mechanic @ a Dearlership in Pensacola. About 1 1/2yrs ago, he told me there were problems / stay away from the Duro prop... Leakage

I have no update on the subject since then.

 

[Mpellet]

What is your top rpm and speed with that prop?

Perfect conditions with 1/2 fuel or less I have touched 35 knots but realistically more like 33 knots. Trimmed up and in calm water 6100RPM at WOT but realistically more like 5900 RPM. Statue miles would be x 1.151 more so 37ish MPH would be a realistic WOT operational speed for my boat. My hull is 19 years old and kept in a slip 6 months a year. The bottom doesn’t typically have any growth but it is painted with petit hydrocoat which is an ablative paint resulting in a bottom surface that is likely a tad slower then an unpainted hull.

Whatever I own, boat, truck etc always seems to get worse performance #s then what people with similar equipment report, so it’s either everything I own underperforms or I report uninflated performance #s, you can make that judgement for yourself.

I suppose that I am ever so slightly overpropped but 17 is lowest pitch available in a 16” Water Grip and having tried a smaller diameter propeller, it ran like crap compared to the 16” with a very noticeable tendency to blow out in turns and cavitate when running in a following sea. The 16” 17 pitch Water Grip performs very well on my boat but in terms of max RPM, I am on the lowish side of the recommended range RPM range at WOT…

 

[Big Block]

Perfect conditions with 1/2 fuel or less I have touched 35 knots but realistically more like 33 knots. Trimmed up and in calm water 6100RPM at WOT but realistically more like 5900 RPM. Statue miles would be x 1.151 more so 37ish MPH would be a realistic WOT operational speed for my boat. My hull is 19 years old and kept in a slip 6 months a year. The bottom doesn’t typically have any growth but it is painted with petit hydrocoat which is an ablative paint resulting in a bottom surface that is likely a tad slower then an unpainted hull.

Whatever I own, boat, truck etc always seems to get worse performance #s then what people with similar equipment report, so it’s either everything I own underperforms or I report uninflated performance #s, you can make that judgement for yourself.

I suppose that I am ever so slightly overpropped but 17 is lowest pitch available in a 16” Water Grip and having tried a smaller diameter propeller, it ran like crap compared to the 16” with a very noticeable tendency to blow out in turns and cavitate when running in a following sea. The 16” 17 pitch Water Grip performs very well on my boat but in terms of max RPM, I am on the lowish side of the recommended range RPM range at WOT…

Awesome thanks... yes mine ran terrible with the stock yamaha prop on the 250... the rev 4 merc made a big difference. These boats seem to need lift, and grip to turn... to me. If you did it again would you contemplate the 350?

 

[Mpellet]

Awesome thanks... yes mine ran terrible with the stock yamaha prop on the 250... the rev 4 merc made a big difference. These boats seem to need lift, and grip to turn... to me. If you did it again would you contemplate the 350?

When you have manufacturers using the same block/weight like they typically do with the 225-300s, I personally don’t see any extra concern about hanging what’s essentially the same engine with different #s on the cowling and a different tune BUT making the jump up to an outboard with different sized engine block and a 150lbs more weight, well IMO that’s a different ball game and one that I personally wouldn’t wanna make my boat the subject of what would be a $30K+ experiment. The structural & trim implications of hanging an engine that weighs approximately 25% more then the class of engine the boat is rated for would concern me.

Bottom line, the extra 150lbs of the 350 would scare me both structurally and in terms of trim and I personally would not attempt to hang a 350 on my boat.

 

[Big Block]

When you have manufacturers using the same block/weight like they typically do with the 225-300s, I personally don’t see any extra concern about hanging what’s essentially the same engine with different #s on the cowling and a different tune BUT making the jump up to an outboard with different sized engine block and a 150lbs more weight, well IMO that’s a different ball game and one that I personally wouldn’t wanna make my boat the subject of what would be a $30K+ experiment. The structural & trim implications of hanging an engine that weighs approximately 25% more then the class of engine the boat is rated for would concern me.

Bottom line, the extra 150lbs of the 350 would scare me both structurally and in terms of trim and I personally would not attempt to hang a 350 on my boat.

I guess I should have been more specific. The Yamaha 350 is 653lbs The Suzuki's are much heavier at almost 790lbs. Neither brand produces a V8 350 anymore... the 350's are just tuned, slightly bigger displacement V6 than their 300 counterparts. The weight is the primary reason I am leaning Yamaha... that and the digital steering adding auto pilot of my garmin setup. The weight diff from 300-350 is negligible though.

 

[warthog5]

One thing maybe Overlooked here..... Suzuki's are Geared Lower.... In Fact they are the Lowest geared Outboards on the market.

With that...They Swing BIGGER props. IE: Yamaha will not swing a 16in Dia prop. Suzuki does. More blade....More Bite.

 

[Big Block]

One thing maybe Overlooked here..... Suzuki's are Geared Lower.... In Fact they are the Lowest geared Outboards on the market.

With that...They Swing BIGGER props. IE: Yamaha will not swing a 16in Dia prop. Suzuki does. More blade....More Bite.

Agreed... but I am a big yamaha fan. I did have an old gray and gold 2-stroke Suzuki 225 maybe 275?... the ones famous for the grenading lower units - but that one became too much for the old Grady transom. The best outboard mechanic I know is also Yamaha... so there's that too.

I also like the offset driveshaft, and the design of the new integrated hydraulic steering on the Suzuki.

It really is a tough choice.

J

 

[FishHeadGreg]

following

 

[Mpellet]

I guess I should have been more specific. The Yamaha 350 is 653lbs The Suzuki's are much heavier at almost 790lbs. Neither brand produces a V8 350 anymore... the 350's are just tuned, slightly bigger displacement V6 than their 300 counterparts. The weight is the primary reason I am leaning Yamaha... that and the digital steering adding auto pilot of my garmin setup. The weight diff from 300-350 is negligible though.

Copy, I assumed we were discussing Suzuki Outboards. That new Yamaha 350 looks pretty sweet….