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We had a customer last year we took his tired two strokes off an installed a set of 225 four strokes. He called us down to the boat for a cable adjustment. It had to be a cable adjustment. He went from 200 yamies to 225 four stokes. He said it lack top end performance we made sure it was set up correctly. He then gave us four weeks to get them of his boat and get his two strokes back on. We put new 200 back on. When I think of four strokes a think of a pontoon boat a cocktail barge. drinks any one. Vinney
This may add to the conversation. In general, internal combustion engines tend to be more efficient, on a specific basis (fuel consumption/power), when operating at or near their highest power setting. So, if you need 100 hp to cruise your boat under certain conditions, you will get better mileage if you use the smallest engine that will give you the 100 hp. If you have a 200 hp engine throttled back to produce 100 hp, economy will suffer.Now I have a question. Supposedly conventional 2-stroke engines built before 2006 will be grandfathered after that date. Only new engines will be required to meet the 2006 spec after that date. Should I trust the government? If I buy a new conventional 2-stroker now, am I absolutely guaranteed that the government will not outlaw it eventually?
JB,When did you become a moderator? Congratulations I guess. Going back to what AUGIDAWG said earlier, about the twin engine boat, with a Bomb and a Yamaha, I heard ( I believe from the Dusky people) that Bomb did that at last years Miami boat show. I forget if it was 2S against 4S or 2S against 2S but Bomb was doing that. Somehow Yamaha got them to stop that demo real quick though.
OK YIKES THIS IS BIG!!! Ok now....2 strokes fire very time the piston is near the top.4 strkes fire every other becuase it needs one stroke to push the exhust gasses out (it makes you wonder why its not called 1 stroke and 2 stroke) THAT extra stroke on the four stroke is it's tougre weekness.On the story about that 4 strokes can not get a boat on plane when side by side, is untrue, this is a boat with a prop that can slip, you can just rev up that way, then it will kick in. if you want a constant torque (notice that I spelled it right that time) look at some Jet turbine engines, in those engines as the RPM increases so does the torque..also most engines are geared and torque is useless, in calculation, also unless full torge of a two stroke is at full rpm, the four stroke can still get on plane just at a higher rpm...did I make myself cleare?
Mes amis nous allons quelque part dont tout
Se rappelle d'un endroit ou l'herbe etait
Et la fete ne s'arretait jamais
A autour du rocher
Comparing outboards, either HP vs. HP or 2-stroke vs. 4 stroke, is almost impossible. No matter what type of comparisons are made, it's never apples to apples.First of all, outboards are sold based on a rated maximum power output. Not power output at idle, troll, or 3/4 throttle. Not power under the load of your particular boat. Not power trimmed, jack plated, or proped. Just max power.More importantly, HP is really a "false" measurement. HP is only a true function of torque and rpm, and it can only be measured by that torque and rpm. When torque and rpm are plotted on a curve, the area under the curve is called "work". So although some outboards may have equal HP in comparison, they will do different work. An outboard with a broad torque ranging over a large rpm band will do the most work. In fact a lower HP outboard may do more work than a higher HP outboard becasue it makes more torque over the entire rpm range.With that said, outboards of exact HP can have totally different torque outputs and operating rpm. For example a 225 HP 2-stroke may make its maximum torque in a very narrow band of rpm. Sure, it has the 225 HP, but only in a specialized area that we might want to use for racing, and not cruising or trolling. A 225 HP 4-stroke may make its maximum torque at a lower and wider band of rpm. This may not be a racing motor, but a very efficient cruiser or troller.Many other apples to oranges factors are involved in comparing outboards....Engine design. V-designs operate much different than I-designs. Although they may put out the same HP, I-designs usually run greater low end torque and lower operating rpm.Compression. Smaller displacement, higher compression engines may make similar HP to larger displacement and lower compression outboards.Operating RPM.Displacement.Fuel intake induction.Weight.Propping.And a biggy that everyone seems to ignore.....gear ratios!So identical HP ratings can mean totally different outboards. Lets not forget that inboards are 4-strokes. There is no way a 250 HP 2-stroke outboard will push a heavy 26' fiberglass V-hull as well as a 250 HP 4-stroke diesel. Why? Because the diesel makes almost 3 times as much torque.If I needed max speed and light weight, and want to save a few $$ the 2-strokes are awesome. But I don't need those things as much as I need maximum, overall enjoyment from my outboards. That's why I have 4-strokes. My own experience with 4-strokes vs. 2-strokes leaves no questions asked.
JB,It will be a discussion that will NEVER end. (Re; Yamaha price-US vs. Australia.)I've got too many irons in the fire.To each, his own-"may the buyer beware".See ya, you won't hear until we solve the 320 electrical problem.
Interesting information here about power differences. Thanks all.JB, exactly what didn't you understand? And who is the they you are referring to everyone but you and Djohns?Djohns, sorry for your attitude and the comparison between this thread and another. I don't see that.Id like to know more about power of these engines.