Why are the Mercury 4 strokes so slow?

[PatriotAW4]

Back in the day most 20-21 foot boats with a 225 2 stroke could easily break 70 mph if set up right, and with a 250 they would run 75-80 mph or more. Examples from past experiences, Javelin 400 with a 225 Vindicator 10" jack plate and worked 26p Raker would run 74-76, Stratos 21 ss with a Mercury 250 XB would touch 80 on the GPS, Stratos 201 Pro with a Evinrude 250 HO was 77-78 MPH, and a friend of mine currently has an 02 21 foot Triton with a 225 Mercury 2 stroke that I have yet to see a single boat with a Mercury 250 4 stroke be able to keep up with. I am constantly reading about people with 20-21 foot boats with 250 Mercury 4 strokes struggling to break 70 MPH and doing over 75 with one is rare unless it's a high end performance hull. What makes the newer motors slower?

[MichAngler]

I think your overlooking much more than just the motor

I have a 06 Skeeter zx250 that when I first got it would do 74+

Add an Ultrex plus 2 large 12” graphs and enough cable/wire to run a server farm on the bow and I’m lucky to get 68

Boats are now designed more for a better ride than speed and you add thousands of pounds of gear with power poles, 4 or more graphs, multiple transducers padded carpet, more rods/reels than you can use in a day and a ton of tungsten weights it’s all got to effect the speed

[Kb444fishing]

stratos, stratos,stratos, just humor i have a stratos 201 underpowered with a 225. Used to think at blast off i would get left behind . not. I think the new four strokes are supposed to be only a couple mph slower, like the guy above said probably a lot to do with weight. And you know that Javelin 400 hull was in a super fast hull anyway.

[ssmithboats]

a lot of the 80 mph boats back in the day were speedometer mph not gps sometimes the memory slips.

[PatriotAW4]

stratos, stratos,stratos, just humor i have a stratos 201 underpowered with a 225. Used to think at blast off i would get left behind . not. I think the new four strokes are supposed to be only a couple mph slower, like the guy above said probably a lot tom do with weight.

Almost forgot about the Pro Craft 210, it ran 75-76 with a 250 Mercury also, didn't ride that great though. Main point is back then pretty much any mainstream bass boat- Triton, Stratos, Pro Craft, Javelin, etc (Rangers and Nitros are an exception) could run mid to high 70s and even in the low 80s with 225-250 hp motors, now with the 4 strokes it seems to be more of a struggle to do that. The guy down the road from me just got a new Caymas CX21 last year with a 250 Pro XS on it and 70-71 is all he has been able to get out of it, runs 68-69 with 2 people loaded, and that seems to be common with most brands of boats now from what I have seen and been reading.

[tdt91]

It's the weight we have on our boats now. All that extra weight up front essentially.

[PatriotAW4]

a lot of the 80 mph boats back in the day were speedometer mph not gps sometimes the memory slips.

No doubt about that, GPS speeds are all I go by.

[hoss1908]

I think today's boats, with GPS maps and speedometers are finally telling the truth.

Most of the guys in the performance boat world are actually running faster with the 4 strokes than they did with the 2 strokes on the same hull.

[HTC33]

Agree with other comments…WAY more weight added to boats today, with the weight in the bow having the biggest impact on speed. And, those speeds quoted on the old rigs are largely speedometer speeds…which are not very accurate. One thing not mentioned above…today’s boats are wider (I.e. bigger) than the boats from yesteryear.

[PatriotAW4]

I would like to add all the speeds I have mentioned were on a GPS, not going by a boat speedometer.

[bass-action]

When I first got my boat I could touch 80 mph with it. Had a Motorguide trolling motor up front with one 10" graph. Now, 2 12" graphs, Ultrex,360 and all the special brackets needed for it. would struggle to reach 75 after adding all that. Now added lithium batteries because my holeshot was dismal and slowed it even more.

[Woody b]

Like others have said GPS speed is real.

[22R]

Shhh!! You are saying the quiet part out loud and most don't want to hear it. The new 4 strokes are quite good and impressive for what they are but pound for pound a 4 stroke cannot compete with a 2 stroke as it fires every time the piston reached the top of the cylinder. I am not knocking the 4's just stating a fact, If the 4 stroke was as good they would have made it in the 2.5-3.5 L range but they had to have more displacement to stay anywhere near the performance of a 2 stroke. A added plus is Merc saw how may more parts are need to produce them, Have you priced any Merc parts lately?


22R

[The5thDutton]

Isn't the diameter of the gearcase larger? That's more drag, too.

[djb750]

Back in the day:
then.jpg

Now:
now.jpg

[Treker47]

2 stroke motors smell better in the morning than 4 stroke.

[Johnnyred]

2 stroke motors smell better in the morning than 4 stroke.

[Bass Cat Boats]

It’s boat size, boat equipment, engine weights, people carry more tackle, plus some of us gained weight (sorry), and they play too much with hydraulic plates today. Fixed plates helped keep setups connected. And we do think they aren’t quite as fudged on horsepower.

[fishnfireman]

Didn't hurt my top end.

[Bass_boat_boy]

2 stroke motors smell better in the morning than 4 stroke.

But the V8 sounds better ....