Yamaha motors

[earthling]

2 strokes are still a 100% oil loss platform. That oil all goes out the exhaust in one form or another.

Conventional 2-strokes are 100% oil loss. There have been and continue to be modernizations of 2-stroke designs which are not 100% oil loss and/or are simply not conventional. An example take on the traditional 2-stroke with the crankshaft providing propulsion is the ryger revo and achates opposed cylinder designs. Then you have hybrid 2-strokes like some of the free piston designs which combine ICE power with electricity generation to create very compact and efficient engines. There have been many takes on clean 2-strokes but like I said earlier, the industry is really just now revisiting 2-strokes to see what is possible. We may see a resurgence of wankel designs (now there is an unintentional oil loss platform) for many purposes now that we have more modern metallurgy and coatings.

 

[Port-Parts]

Something very important hasn't been mentioned here.
Emissions standards were put in place that were to get more strict as years went on. Yamaha realized that NO 2-stroke could meet those standards so they dumped all their money into 4-strokes. They were right.........BUT, the big companies lobbied to get those standards lowered and Yamaha got caught with their pants down.

Also playing an important part in the lack of follow through on the emissions standards getting more strict was the decline in snowmobile sales (especially in the US) that has happened since those standards were put in place. Back between 1995-2005 there were 120-160K snowmobiles sold per year (mainly 2 strokes) in the US by all 4 manufactures - since 2009 the US market has only had roughly 45-60K snowmobiles sold per year (4-strokes included) - which has lead to less focus of cleaning up the 2 strokes.

 

[Vmax]

A newer 2 stroke can't be 100% oil loss, doesn't the piston rings, crank bearings etc. absorb some of the oil?
As per Port-Parts comments regarding the lack of sled sales, the first thing that comes to mind is the weather change.........here in Southern Ontario we do not have the winters that we used to. A few good ones mixed with a few bad ones, so I can understand why folks are not willing to dish out 15+ K for a sled you may only use every other year at best

 

[Handy]

The metal components that you mention can only absorb an amount of oil to fill the pores in the metal, once the pores are full of oil (usually during break in) the engine becomes a 100% oil loss system. A sponge can only hold so much liquid then the rest just bypasses.

 

[Vmax]

Sounds reasonable..........thanks for sharing

 

[Vmax]

It still makes me wonder why Ski-Doo, Polaris and Arctic Cat have put some much research and money into the 2 stroke sled engine. The sled riders are still asking for these engines, evident by the sales each year. Compared to the old 2 strokes the new E-Tec (Ski-Doo), C-Tec (Cat) engines are very clean, great on gas (but still burn oil), super fast and are low end stump pullers. For us 2 stroke fans it gives us life to know that three of the four sled manufactures still see the need for this engine that has made snowmobiling what it is today.
It will be a sad day if the 2 strokes are phased out but I can honestly see it coming. With the birth of the 4 stroke becoming lighter and more fuel friendly , the end is near.

 

[20/80]

2 Strokes tend to start a lot easier in the extreme cold compared to 4 strokes, the 4 stroke camp are working on that though, trappers and people that live in the far north favor the basic leaf blower 2 strokes, easy to rebuild out in the bush if need be, 2 strokes will be around for awhile yet.

 

[stevewithOCD]

2-strokes are not leaving the sport.
Although in the "big" trail areas, the sleds under 5 years old, i'd guess are now over 50% 4-strokes. If Polaris gets their 4-stroke game on, i believe that number will be in the 75% range.
BUT, don't forget these few things.

1. 50% of the sleds i see out there are more than 5 years old pushing the "big" trail 4-stroke numbers down to 30 to 40% ish.
2. "big" trails only make up less then half the trail riding population.
3. As long as there are mountains.......there will be 2-strokes.
4. As long as some people only put less than a 1000 miles per year on smaller bumpy trails, 2-strokes will be around.
5. As long as back woodsman, like 20/80 says, that need simplicity & low cost are around......2-strokes will be here.

to sum it up:

Four strokes are:
1. heavier....period
2. cost more ....period
3. are more complex....period..... needing a battery that freezes in extreme cold

ALL this means the Two's are here to stay UNLESS the Feds put extreme emissions standards into place like they did 20 years ago then reneged on & that's why Yamaha doesn't make two strokes anymore anyways....

 

[biffdotorg]

Don't forget that Yamaha is #1 in world boat motor sales & they are all 4-stroke.

Yamaha is a world leader in outboard motor sales because they make and sell both 2-stroke and 4-stroke. A leader in the world, means you have to look at what is sold all over the world. And they still make one of the most reliable 2-stroke motors in an outboard. (just probably not in the US)

https://yamaha-motor.com.au/products/marine/outboard/mid-range-two-stroke-25---90hp

 

[stevewithOCD]

Yamaha is a world leader in outboard motor sales because they make and sell both 2-stroke and 4-stroke. A leader in the world, means you have to look at what is sold all over the world. And they still make one of the most reliable 2-stroke motors in an outboard. (just probably not in the US)

https://yamaha-motor.com.au/products/marine/outboard/mid-range-two-stroke-25---90hp

Very few of us realize Yamaha still makes 2-strokes. I don't think they upped the technology in years and i don't think they make big HP motors either, but they still make them.

 

[Sasquatch]

2-strokes are not leaving the sport.
Although in the "big" trail areas, the sleds under 5 years old, i'd guess are now over 50% 4-strokes. If Polaris gets their 4-stroke game on, i believe that number will be in the 75% range.
BUT, don't forget these few things.

1. 50% of the sleds i see out there are more than 5 years old pushing the "big" trail 4-stroke numbers down to 30 to 40% ish.
2. "big" trails only make up less then half the trail riding population.
3. As long as there are mountains.......there will be 2-strokes.
4. As long as some people only put less than a 1000 miles per year on smaller bumpy trails, 2-strokes will be around.
5. As long as back woodsman, like 20/80 says, that need simplicity & low cost are around......2-strokes will be here.

to sum it up:

Four strokes are:
1. heavier....period
2. cost more ....period
3. are more complex....period..... needing a battery that freezes in extreme cold

ALL this means the Two's are here to stay UNLESS the Feds put extreme emissions standards into place like they did 20 years ago then reneged on & that's why Yamaha doesn't make two strokes anymore anyways....

Thats a lot of Periods are you trying to say something!

 

[Sasquatch]

2 Strokes tend to start a lot easier in the extreme cold compared to 4 strokes, the 4 stroke camp are working on that though, trappers and people that live in the far north favor the basic leaf blower 2 strokes, easy to rebuild out in the bush if need be, 2 strokes will be around for awhile yet.

Partly true! At -40 even two strokes are very hard to pull over. Now My Warrior started at -40 with no problem and my Apex does but for some reason it likes to flood itself when it starts then stalls. Not every time but often enough! Pull fuel relay crank it over then reinstall relay it goes, might have to do that a couple times. The Doo 1200's always fired right up at -40! The sweet part with the Warrior was carbs and a choke you can control.

 

[Sasquatch]

Very few of us realize Yamaha still makes 2-strokes. I don't think they upped the technology in years and i don't think they make big HP motors either, but they still make them.

You can buy a VK 540 workhorse and it has not changed since about the 1980's, only two stoke left this side of the pond!

They also build Yamaha four stroke sleds that they sell on the other side of the pond. Unfortunately not for sale here!

 

[20/80]

Partly true! At -40 even two strokes are very hard to pull over. Now My Warrior started at -40 with no problem and my Apex does but for some reason it likes to flood itself when it starts then stalls. Not every time but often enough! Pull fuel relay crank it over then reinstall relay it goes, might have to do that a couple times. The Doo 1200's always fired right up at -40! The sweet part with the Warrior was carbs and a choke you can control.

You got that right they are hard to pull over at -40, but I think the oil gets to the engine quicker on a 2 stroke the pre mix ones for sure compared to a 4 stroke in the very cold, a 4 stroke at -40 would be hard to pull over with a pull start I would think, not cheaping out on a quality battery would play a big role in the cold in a 4 stroke, haven't seen -40 here in along time.

 

[CaptCaper]

A newer 2 stroke can't be 100% oil loss, doesn't the piston rings, crank bearings etc. absorb some of the oil?
As per Port-Parts comments regarding the lack of sled sales, the first thing that comes to mind is the weather change.........here in Southern Ontario we do not have the winters that we used to. A few good ones mixed with a few bad ones, so I can understand why folks are not willing to dish out 15+ K for a sled you may only use every other year at best

They don't loose it they burn it.. I can smell the oil in my helmet from them...yes the newest machines I'm talking about.. just a fact.