Are 4 strokes starting to win ?

[Bigtalljv]

OK, sounds like usage is the problem here. I don't go out in the rough stuff, can't dive in it anyway.

Jason

[Wibs]

Originally Posted by matt h

The suzi 50 only pushed out 42 at the prop but the twatsoo does 50hp so you will feel the difference.

Why do they do this....?

I used to ride motorbikes and some manufacturers would quote BHP at the crank....some at the rear wheel..?


Pretty sure this thread will end up in the bilges as another Etec vs The rest of the world debate.


There.......I said it.

[chris123]

Originally Posted by Landlockedpirate

Yep, its a fair point. But the 15hp, 4 stroke Yamaha is now just 39kg, down over 12kg on its lardyarse previous version.
So they are getting a lot closer.

Is this a new model? The 15HP 4 stroke on Yamaha's website (F15C) is still 51kg? Any more info?

Cheers

Chris

[PeterM]

Yes the new four stokes give more pros than cons compared to 2 strokes. The verado 200 has as much poke as the opti but is much smoother and happier at low revs...

[Searider]

Originally Posted by PeterM

Yes the new four stokes give more pros than cons compared to 2 strokes. The verado 200 has as much poke as the opti but is much smoother and happier at low revs...

But much more costly to purchase.

[Landlockedpirate]

Originally Posted by chris123

Is this a new model? The 15HP 4 stroke on Yamaha's website (F15C) is still 51kg? Any more info?

Cheers

Chris

Its the number thrown at me by a Yam dealer when I was in the States earlier in the year. I cant find any reference to it on the net, but he mentioned it was part of the weight saving that has been applied to the mid range stuff.

Not convinced its a real number, saving 20% on the existing weight is a big ask.

[Searider]

Originally Posted by Bigtalljv

Why is hole shot so important? It's always the first thing 2 strokes are said to be superior in. when I go in my boat it's usually to go somewhere. the hole shot is 8 seconds of a day trip. Why do I care if it's 8 seconds or 12?

I'm running a 250hp 4-stroke so maybe this is a portable engine conversation?

jason

Hole shot is important when you don't have so much excess power.

I would guess that 250hp on your 7.5m is plenty of power.

But start looking at 135hp or maybe 150hp on a 7m and all of a sudden the "holeshot" or low / mid-range torque is more important.

[Pikey Dave]

Originally Posted by Peter_C

Of course the direct injection 2 strokes are completely different, but even they barely meet the emission standards put forth today.

Really Here we go again

[Peter_C]

Originally Posted by Pikey Dave

Really Here we go again

Do you have emission standards for boats in the UK?

A new boat sold in the USA must meet an emission standard and many today are coming with catalytic converters on them. Our emission standards being far stricter, or consider it better for the environment, are the reason you won't see hardly any diesel cars as they can't burn clean enough to pass our environmental protection laws aka the E.P.A. Since this is a forum that is global, we all must look at the world wide responses. What happens in the U.K. and the USA are two separate issues.

[Landlockedpirate]

Originally Posted by Peter_C

Do you have emission standards for boats in the UK?

A new boat sold in the USA must meet an emission standard and many today are coming with catalytic converters on them. Our emission standards being far stricter, or consider it better for the environment, are the reason you won't see hardly any diesel cars as they can't burn clean enough to pass our environmental protection laws aka the E.P.A. Since this is a forum that is global, we all must look at the world wide responses. What happens in the U.K. and the USA are two separate issues.

Necessity is the mother of invention

Once your gas prices hit $10 per gallon, you will find a lot more oil burners on your roads. Diesels over here are generally cleaner than petrol engines (thanks to some really clever tech) and actually have lower tax bands because of it.

Take the 6 cylinder 3.0L BMW engines. The diesel is more powerful, more economical and cleaner than the petrol.

Europe have had emmisions targets longer than the USA for road engines, marine restrictions came in in 2006, just like you.

[Bigtalljv]

<sarcasm>Diesels are not popular in the USA because people have seen black smoke come out of the old ones and the exhaust of the gasoline cars is invisible and black must be worse than invisible so the have legislated the black away. </sarcasm>

[Peter_C]

Originally Posted by Landlockedpirate

Once your gas prices hit $10 per gallon, you will find a lot more oil burners on your roads. Diesels over here are generally cleaner than petrol engines (thanks to some really clever tech) and actually have lower tax bands because of it.

Take the 6 cylinder 3.0L BMW engines. The diesel is more powerful, more economical and cleaner than the petrol.

Europe have had emmisions targets longer than the USA for road engines, marine restrictions came in in 2006, just like you.

Well I know for a fact that the USA standards for vehicle emissions are really tough to meet. Very few diesel car engines do not meet our standards period. Plus diesel is more expensive then the 15-20% efficiency increase makes up for.

"The USA's 50-state light-duty diesel vehicle limit for emissions of nitrogen oxides is 0.07 grams per mile. In Western Europe, the limit is 0.29."

[Landlockedpirate]

Originally Posted by Peter_C

Well I know for a fact that the USA standards for vehicle emissions are really tough to meet. Very few diesel car engines do not meet our standards period. Plus diesel is more expensive then the 15-20% efficiency increase makes up for.

"The USA's 50-state light-duty diesel vehicle limit for emissions of nitrogen oxides is 0.07 grams per mile. In Western Europe, the limit is 0.29."

I'm no expert, but I can read and the EPA and EU both publish the emissions tech specs, so here goes......

99% of the EU regulations are far tougher than the EPA, with the noteable exception of NO. I wonder why this is ?

Putting an artificially low NO target into the mix seems strange until you realise that this single action has effectivly banned diesels in the USA since 2007. But why would the USA want to 'ban' diesels I hear you ask.

Hmm, good question. Why would a country that is the worlds 3rd largest oil producer, selling 3 Billion barrels of oil a year want to 'ban' a technology that reduces the amount of fuel its cars would use ? I really cant guess, can you ?

Any emissions targets that effectivly banned 70mpg diesel cars, but allowed 14mpg SUV's are not looking at the big picture. A car that burns 2 gallons for every 150 miles is more environmentally friendly than a car that burns 10 gallons for the same distance. Its just simple maths.

Fortunately manufacturers seem to have jumped through hoops and the latest generation diesels exceed the targets and are legal, unfortunately they do seem to be a lot more expensive than their petrol counterparts.

This really isnt a knock America post, I love the States, spend a couple of weeks there a year, my main boat is American, I have owned an American car and even a couple of the dirty 2 stroke oil burners in my shed are American. However, sometimes you need to realise that there is a whole world out there beyond the red, white and blue stars and stripes shores.

You have got to love thread drift, from lighter 4 strokes to International emissions regs

[spartacus]

Originally Posted by Rogue Wave

I love 2 strokes and I could cut my tounge out for what I am about to say but yep I think 4 strokes are getting there. We have a Yammie F70 which is only 10% heavier than our 2 stroke Yammie 70 and easily has the same power and torque. In addition to that it uses about a third of the fuel, which makes me very happy as it cost me me so much less to run the boat. Oh yeah and it's good for the environment!

The F70 is a fantastic engine and provides the blueprint for mid-horsepower outboards for power to weight ratio, emissions, noise levels and of course fuel efficiency.

Only trouble is a new F70 will set you back anything from £7-8k. That's a lot of fuel, and considering running a boat is never going to be cheap, it's a big commitment for what is a relatively short season all things considered, certainly here in the UK.

Back to the OP. Yes, 4-strokes are undoubtedly the future... says the man who permanently has oil under his fingernails from tinkering on 2-strokes.

Still love my Tohatsu. Its basic build is invaluable to learn the basics of maintenance through to full rebuilds, just look at Roflhat's rebuild thread on his 50D. No need to plug it into a laptop or pull error codes. At 118kg the M60 is no heavyweight compared to older style 4-strokes. It's still frugal enough as long as it's not running at WOT, and will provide many years of reliable service. The 2-stroke will still be here for years to come, and long may that continue.

[jamool]

Originally Posted by Peter_C

4 Stroke all the way! Environmental reasons should be the number 1 reason for them. I feel guilty every time I start my 2 stroke up and see a sheen of oil on the water.

I was reading another thread where the guy has to have a 4 stroke in order to run it on local lakes in Portugal. Some of our cleanest lakes here in the USA have banned 2 strokes also. It is a trend that will continue.

Of course the direct injection 2 strokes are completely different, but even they barely meet the emission standards put forth today.

from what i understand 2 strokes leave 20 - 30% mix un-burnt in the water however does this not evaporate into the air? I though they were more of a problem to air quality than water quality?

[Peter_C]

Originally Posted by jamool

from what i understand 2 strokes leave 20 - 30% mix un-burnt in the water however does this not evaporate into the air? I though they were more of a problem to air quality than water quality?

The fuel and oil are first dumped into the water. From there they float to the surface. Although the fuel itself may evaporate fairly quickly the oil is left behind.

My 2 stroke I would say runs pretty well, but on first start when cold, with the choke on for a few seconds it dumps a ton of extra fuel which means extra unburnt oil into the water. I can often see a sheen around the back of the boat. I felt really guilty one day launching in a marine reserve/dive park, as I launched, started the boat, and had just a little bit of trouble getting it to idle, so it puked extra fuel out. The sheen was all over the water as a few scuba divers entered the water right thru the middle of the oil slick. They didn't say anything, they may not have even noticed, but I sure did. It sucks to care about the world around you

Funny story; one day I was launching at a local boat ramp to test drive the boat. So I back my Prius up to the water and a homeless bum with a 40oz beer in a brown paper bag goes "I sure hope that's a 4 stroke on yer boat" (He knew exactly what it was and starts...) Me *sigh* "Nope".

[jamool]

Originally Posted by Peter_C

The fuel and oil are first dumped into the water. From there they float to the surface. Although the fuel itself may evaporate fairly quickly the oil is left behind.

My 2 stroke I would say runs pretty well, but on first start when cold, with the choke on for a few seconds it dumps a ton of extra fuel which means extra unburnt oil into the water. I can often see a sheen around the back of the boat. I felt really guilty one day launching in a marine reserve/dive park, as I launched, started the boat, and had just a little bit of trouble getting it to idle, so it puked extra fuel out. The sheen was all over the water as a few scuba divers entered the water right thru the middle of the oil slick. They didn't say anything, they may not have even noticed, but I sure did. It sucks to care about the world around you

Funny story; one day I was launching at a local boat ramp to test drive the boat. So I back my Prius up to the water and a homeless bum with a 40oz beer in a brown paper bag goes "I sure hope that's a 4 stroke on yer boat" (He knew exactly what it was and starts...) Me *sigh* "Nope".

I have noticed that my test tank is covered with a bit of oil after running the outboard for a few mins.

I though this was quite interesting from mercury in 1998 (guess there has been quite a bit more evidence since this was written):

While the EPA is refraining from comment, the marine industry isn't taking the lawsuits lying down. "We are, in this industry, outdoorspeople, conservationists, and environmentalists," emphasizes Mercury's Esposito. "Eighty percent of the two-strokes we sell are used for some fishing. We have an extremely high stake in making sure that our waters remain healthy so people can continue to fish so they'll continue to buy engines. So we're involved with a number of environmental and conservation groups and work very closely with them. Not only is it the right thing to do, but we have a vested interest in it from a financial point of view. Good waterways ensure that people are out there boating and fishing and skiing and all of the other things they use a boat to do."

Esposito adds, "Exhaust from an outboard doesn't effect water quality. When those hydrocarbons hit the water, the unburned fuel is what it is, virtually all of it evaporates almost immediately, and the balance of it evaporates in like the next 10 minutes. So you see this little sheen out there on the water, but the hydrocarbons evaporate into the air, not into the water, and that's why it's an air-quality issue, not a water-quality issue. The one EPA study that was done bears this out. No impact on wildlife, no impact on plant life. It's strictly an air-quality issue."

The distinction Esposito makes between air-quality and water-quality is echoed by Bill Rush of OMC, who points out, "The hydrocarbon emissions from outboard motors and PWC are really categorized into three categories - hydrocarbons, carbon monoxide, and NOx. Most people's attention has been focused on hydrocarbons. Hydrocarbons are also a class of chemicals called volatile organic compounds (VOCs). By their very nature, VOCs evaporate from wherever they are, on the ground or in the water, and go into the air. That's why the EPA recognized this is an air emissions issue. All the evidence still points to that and there's nothing to cause us to think any differently."

[jyasaki]

Originally Posted by Peter_C

Funny story; one day I was launching at a local boat ramp to test drive the boat. So I back my Prius up to the water and a homeless bum with a 40oz beer in a brown paper bag goes "I sure hope that's a 4 stroke on yer boat" (He knew exactly what it was and starts...) Me *sigh* "Nope".

Dammit, Pete; now I'm going to think of that every time I see your rig...

jky

[Peter_C]

Originally Posted by jyasaki

Dammit, Pete; now I'm going to think of that every time I see your rig...

jky

Since my car has high miles (138K), I don't tow with it much anymore. Our new Prius C is too small. So most of the time I use Kieth's pickup (Free gas!), or my friends wife's Murano, that I setup to tow. Neither get over 30mpg while towing though, like the Prius does.

[Pikey Dave]

Originally Posted by Peter_C

The fuel and oil are first dumped into the water. From there they float to the surface. Although the fuel itself may evaporate fairly quickly the oil is left behind.

It sucks to care about the world around you

Buy an Etec then