sledheadgeorge
TY 4 Stroke God
And that diff can be made up with a smaller gas tank. 4 strokers get better milage and gas weights??????????? about 7-8 lbs a gallon.
Red2003
TY 4 Stroke Guru
YZ450F is 9 lbs heavier then Yz250, but that's dry weight. It'll be more then that when you add engine oil. But let's make it 10 lbs for sake of arguement. That 10 lbs on a dirtbike is on a single cylinder engine and thats on a 200 lb bike. That's 5% heavier. 5% in racing is a lot. Especially when you get that 5% bouncing up and down. I'd have to see a lighter 4 stroke race sled to believe it.
sledheadgeorge
TY 4 Stroke God
I think if they are all (race sleds) within the same range (1-20lbs) the only real diff will be in the rider.
Roadrunner
Expert
welterracer said:
Well "Johnny", people said Yamaha couldn't build a high performance 4 stroke that weighed less than a 2 stroke and guess what, they did. I'd say they could build it, if they WANTED to.
The question is, do they want to ?
Red2003
TY 4 Stroke Guru
Where's the hi perf. 4 strokes that weigh less then the two strokes? They don't have them all beat yet. It only makes sense that an engine with more parts inside will weigh more then one with less parts inside. Can you make lighter parts? Sure, but at what cost to reliability. Look what has happened to the nice, new lighter mono rear suspension that Yamaha gave us.
Roadrunner
Expert
Red2003 said:
Never said they had them all beat, compare the weight of the 06 RTX or Vector to the Mach Z and Fusion and they only have 2 cylinders. Did you expect a 1000cc 4 stroke to weigh what a 440 or 600 2 stroke will weigh ? Lets at least try to compare apples to apples.
Look at what the other manufacturers 4 strokes weigh. I'd have to say, Yamaha's sure come a lot further weight wise than most people give them credit for doing. And for the 470 pound 2 strokes do you think they maybe made them lighter and also sacrificed some durability ?
Red2003
TY 4 Stroke Guru
Your on the wrong post. We're not comparing Yamaha 4 strokes to other manufacturers 4 strokes, we're comparing a 4 stroke Yammy Race sled to their 2 Stroke race sleds. Its apples to apples. And to answer your question, yes they will be expected to compare 440 cc 2 strokes to 800+ cc 4 strokes. Thats how it works. Hello?????
JDKRXW
TY 4 Stroke Junkie
Red2003 said:
But (and I am estimating a little bit here) the weight of the engine/transmission as a percentage of the weight of the total machine is much greater on an MX bike than it would be on a sled.This means the weight penalty of a heavier engine on a snow-X sled is not as bad as you might think.
btw, the weight difference between a CR450F and a CR250R is LESS than 5 lbs.
Red2003
TY 4 Stroke Guru
Tired of playing with you. When Yamaha produces a competitive four stroke sled lighter then a 2 stroke race sled, I'll believe it. Not before and until.
Mikey
TY 4 Stroke Junkie
Dont forget boys that they are not gonna race 440s in a couple years its only gonna be 600stock and 600 mod . I doubt that yammie will try to make em as light as the 440 they will more likely weigh a lil more than the 600s lets say 10-20lbs. And never say cant cause someone always can its just if its feasible and priced correctly.
sledheadgeorge
TY 4 Stroke God
ITS ONLY A MATTER OF TIME AND IT WILL HAPPEN. 
LazyBastard
TY 4 Stroke God
Red2003 said:
You missed the point.
RX1 : MachZ = YamRace : OtherRace.
(apples : apples) = (oranges : oranges)
Since RX1 weighs less than MachZ... apples to apples... it follows that a Yam race sled will weigh less than other race sleds, oranges to oranges.
They've already shown that a 4-stroke 4-cyl sled can weigh less than a comperable 2-stroke 2-cyl sled of equal displacement.
Now lets think about how we can apply this to a race sled;
if we are looking at 440's (for example), Yam has the capacity to make a 440cc 4-stroke (we're talking about the whole sled) weigh similarly to (less than) a 440cc 2-stroke, even with double the number of cylinders.
Now that will probably not make enough power, so lets change that configuration a little... a 2-cyl 4-stroke 440cc, but add a turbo. Are we in the same ballpark now? I think we are.
Roadrunner
Expert
Red2003 said:
Wrong post ???????? :ORC
If you go back and look at my 1st post, I was merely trying to say that Welterracer sounded a little like Johnny Skeptical as far as the 4 stroke goes. Too heavy etc. and then in my second, I went on to show where the Yamaha 1000cc sleds are equal in weight (and close to the same horsepower) to the other 900 and 1000cc 2 strokes. People like you said it couldn't be done, quess what, you're wrong!!!
If they can get close to the same weight in the bikes why not on the sleds ?
I only threw in the comparison between the other manufacturers 4 strokes to show how Yamaha's ability to remove weight and make more horsepower is ahead of the others and why you shouldn't be so skeptical.
Just because Yamaha doesn't make something, doesn't mean they can't. They build the sleds that their marketing people say are appropriate and will make them money.
sledheadgeorge
TY 4 Stroke God
LazyBastard said:
YOU ARE ON THE RIGHT TRACK LB, THATS WHY BRP HAS ALREADY ENTERED A FORMAL PROTEST TO KEEP 4 STROKE TURBOS OUT OF SNOWCROSS
THE PLOT THICKENS
Red2003
TY 4 Stroke Guru
Like I said, when I see it I'll believe it. LB your rational of apples to oranges = anything makes no sense. To begin with RX1:Mach Z = RX1 loses! Your equation breaks down at that point and beyond. Now if the RX1 or Apex or whatever was lighter and had equal power to a Mach Z, that might be something to get excited about. As far as turbos go, of course they wont let them in and an equal cc turboed 4 stroke would get creamed by a 2 stroke anyway. My opinion. Keep it coming.
