2 Cycle is King over 4 Stroke by my comparison formula.

[David - WI]

Without a catalytic converter maybe not, but we know for certain (at least on newer motors) there is going to be less oil in the exhaust stream on a 4 stroke.

Ultimately though as long as the general public and idiot politicians think they are cleaner then that perception is key and what is being sold as part of the marketing.

Possibly, but there are "smokeless" and "biodegradable" two-stroke oils... and you still have to dispose of the four-stroke oil after an oil change.

Biodegradable oils (so far) don't work very well in four-strokes because they make sludge (as they start to 'biodegrade' after a while in the motor, I guess).

I think, environmentally, these four-stroke outboards would be lucky if they could match the DI two-strokes overall.

[LakeFever]

Theres massive appetite in the dirt bike world for new two strokes. For the boat crowd the beta vhs comment rings a bit. Beta was locked by Sony, much more expensive too. Two strokes are cheaper to build, cheaper to buy, cheaper to run, have less manufacturing carbon footprint, and are not locked by anyone.

the only hill to climb is consumer education. The emission facts will keep the epa types on board so to speak. Plus innovation is still alive and well. Twenty years from now who knows how clean they could be made

[David - WI]

I agree they are missing something in that market segment. I can tell you that my son's STV Pro Comp with a 200 4 stroke has run 106 and has more in set up "my guess is that we will get it to 110". My brand new STV Pro Comp with 200 back in 89' with cut heads, drilled can for exhaust relief, boyesen reeds, and hood vents ran a best of 94 mph.

Joe

Assuming the new Pro Comp isn't 250# lighter than your old one and the prop on the new boat didn't cost more than the motor on your old boat... and your son isn't a better driver than you were then; it must be the motor!

But seriously, I do wish we could find somebody running a similar boat with a 200 Opti and a high- dollar prop for a more apples-to-apples comparison. Right now there are no "cutting-edge" two-stroke outboards to compare these four-strokes too.

[JPEROG]

The propeller is definitely better today. We had two choices back then (cleaver or chopper). Boat weights are the same, mine might have been a little lighter (boats are like women--very seldom do they lose weight with age).

Joe

[David]

I think Mercury is going back to Mr Kiekhaefer's roots and giving the customers a 'bonus'. Mr Kiekhaefer deliberately under rated engines so for example his 10 HP would be faster than any one else's 10 HP. My 200XS ROS probably makes more than 200 HP. A bunch more if this dyno curve I downloaded from here is real. If a 200 4 stroke could out run my 200, it's even further from 200 HP.

[LakeFever]

My 9.8 Merc runs circles around my 9.5 sport twin of similar vintage. My old chrysler 9.9 was faster yet

[David - WI]

Maybe it's just a ratings game, but a 2.5L 200 will walk away from a 2.4L 200 because there is so much more "power under the curve"... you can run props on a 2.5L that a 2.4L just won't pull.

200 "peak hp only tells half the story.

[Z06man]

Your Dyno is right on from what I have heard 235 to 243 .You got the last of those and if I recall it is a 15 incher

[JBS]

Never have stock outboard boats gone faster then with today's 4 stroke power. No debate, just proven fact.

Joe

This. End of storey .It took a while, but they did it.

[pcrussell50]

It didn’t have to take a while. The technology was always there… If you were willing to go big enough and heavy enough. They did have to start building a new class of boats to float the weight, but the technology was always there. With enough weight and displacement, and bigger boats to float it, anything is possible.

-Peter

[LakeFever]

How fast do you want to buy? Two stroke/four stroke/turbine whatever your poison with enough dough they can all be the fastest. Dollar for dollar naturally aspirated two strokes are cheaper to build than four strokes because of substantially leas parts. Less carbon to build these parts, less materials taken from the earth, less cost to the consumer which is less carbon due to the work they must do to make money, less weight to move means leas carbon spent, lighter boats less material leas carbon, i could go on and on theres a lot of ways to look at this where four strokes dont look great.

that said to be clear, my new tritoon will be four stroke powered. What i dont get is why it has to be one or the other. Thats the only insane aspect of this discussion. They are both great but naturally aspirated dollar for dollar id bet on two stroke to win the race every time as long as we are racing that is and not moving equal weight

[David - WI]

The biggest speed upgrade right now seems to be the $6,000 (or $10k) CNC props.

[pcrussell50]

Less carbon to build these parts, less materials taken from the earth, less cost to the consumer which is less carbon due to the work they must do to make money, less weight to move means leas carbon spent, lighter boats less material leas carbon,

All true as can be. Just to add one more thing… In the “reduce recycle reuse” triangle, by FAR the least impact item is the reuse part. It’s much greener to keep using something already built, than to junk it when it can still be used or rebuilt*. This aligns with your analysis of the resources it takes to create new products when the old ones who resource cost has already been amortized, are still serviceable. A mate of mine, who also happens to be an significant environmentalist, learned on day one of graduate school in economics, that “destruction of useful assets is almost never a net plus for society”.

*Of course, the “I want something new” mindset plays very handy to those of us with classic hulls like Hydrosreams, Allisons, classic Whalers, etc… Because we can swoop up still-good motors that someone else didn’t want to clean the carbs or replace a melted piston. Although it scares me how many are scrapped for something like a piston, and then nobody gets to benefit.

-Peter

[FMP]

You never tried the Force from Chrysler 25HP triple Lightning, 94lbs 6400rpm Merc 25 lower... Ripps and idles smooooth with triple spacing.

[FMP]

This. End of storey .It took a while, but they did it.

We can build a two stroke that will mash that claim and do it better in all respects with displacement and fuel burn and area under the curve for torque and emissions, I guarantee it.