STORM-CHASER
TY 4 Stroke Guru
SKIDOO 10)
YES IT IS
The Story Behind the Development of the 2003 Yamaha RX-1
On January 3, 2002, at their remote northern-Wisconsin test facility, Yamaha Motor unveiled to the press the radical 2003 RX-1 as a new flagship of its snowmobile product line. A completely new engine specification for snowmobiles was found in the Genesis Extreme four-stroke powerplant. This is mounted in a newly developed “Delta-box” chassis, a lightweight, high-rigidity aluminum frame packed full of Yamaha’s most advanced design technologies. The result is a new breed of supersport snowmobile that takes performance to an all-new dimension. Where did all of this technology come from? In the Spring of 1999, a team of engineers was brought together to resume work on a four-stroke snowmobile project that would become the 2003 RX-1. Separate teams were set up to handle engine design, chassis design, suspension design and drive system design. Each of these teams was appointed a project chief in charge of design and another in charge of running tests. The project seemed to be right on track with no major surprises……..
Snowmobile development project leader Takuji Nakano was just returning from a week of vacation, booting up his computer and checking e-mail for the first time. He couldn’t believe what he was reading. “Let’s develop our next snowmobile production model around the YZF-R1 engine!” Is this for real? He asked himself.
As of the week before it had been decided to go ahead with the development of a 4-stroke engine snowmobile and the initial design drawings were nearing completion, but they were not for an in-line four-cylinder engine like the R’1s. This meant a complete turnaround in the product concept, but top management had given it the final “Go” sign and the project was on. Yamaha was not only going to produce and sell the world’s first high-performance four-stroke snowmobile, but they were going for the ultimate high-mark by utilizing their dominant YZF-R1 technology. They had been researching and developing four-stroke powered snowmobiles for years, but they were waiting for the “right” time for such a vehicle. Could the North American snowmobile market finally be ready for such an assault?
New 4-Stroke Based on 20 Years of Research
After carefully researching the marketplace, Yamaha decided to go with the plan of developing a 4-stroke model that would bring a new level of excitement and quality to the snowmobiling experience. That meant not just fitting a 4-stroke engine into a conventional snowmobile body but developing a completely new kind of machine to define a new category; the “4-stroke snowmobile.” This would be more than simply powering an existing snowmobile with the R1 engine; it would fulfill a dream that had actually begun some 20 years before.
In Mr. Nakano's words, “This new model represents the realization of an entirely new type of snowmobile, born of the know-how gained from four 4-stroke snowmobile R&D projects over the course of 20 years and brought together around piece of raw material: the R1 engine. That is what you have in the RX- 1.”
Mr. Nakano tells us about that two-decade history. “Our first 4-stroke snowmobile R&D project dates back to 1979. That was followed by similar projects in 1990, '98 and '99. In the '79 project we worked around a prototype mounting the 2-cylinder engine from the GX400 motorcycle. From this we realized that we could indeed get a quieter, cleaner-running snowmobile, but it still left a lot to be desired in the area of acceleration. In the '90 project we used the engine from the FZR400 but were unable to clear our target performance goals in the areas of drive feeling and low-temperature starting. Then in '98 we started another R&D project, again using a sports model engine. But the final weight of 380 kg left serious fears that the performance as a sports machine would be spoiled.” So, once again plans for a production model were shelved.
The project that finally led to the development of the new RX-1 got its start in 1999. “At the start of the project we were working on the premise that we would be mounting a 2 or 3-cylinder power unit. But just as we had verified the direction the final product would take and had started to work with an eye on eventual production, we were suddenly told that the decision had been made to go with the 4-cylinder R1 engine. I have to admit I was more than a bit surprised at first,” recalls Nakano.
“At the same time the move inspired us; if we are going to develop a new machine, what better starting point than to build it around Yamaha's most advanced engine. I thought, here would be a great chance to use this engine's light weight and high performance to build an entirely new type of snowmobile that broke the mold and offered a completely new type of riding excitement and fun.”
Developing a compact, snowmobile-specific engine
The R1 engine could not be used for a snowmobile just as it was. The places and principles under which it would be run are quite different, not to mention the average temperatures of the use. The R1 has a 6-speed transmission but on a snowmobile it would be driving the sled's track through an automatic centrifugal V-belt transmission. It would also carry the disadvantage of being heavier than a 2-stroke. “In a straight comparison with a 700cc 2-stroke engine, the 1000cc 4-stroke is about 10 kg (22 lb) heavier. Our job was going to be to find a layout that would be as compact as possible and reduce the front-end weight as much as possible in order to get handling that was nimble and sporty,” says Mr. Nakano.
“We went through so much trial and error just to determine the best positioning for each axis; not only where the crank shaft and the drive shaft should be but also the cam shaft and the water pump, etc. There was even one proposal to put all three of the main axes, the crank, drive and clutch, on the same axis. Eventually we were able to reduce the engine height by 50 mm by giving it a dry sump lubrication system that requires no oil pan. And, we mounted it the reverse of how it sits on the R1 to bring the exhaust system to the rear. When we tried the idea of mounting the engine with a low center of gravity and as close to the center of the sled as possible, we realized we had found the ideal position,” he adds.
In this way, the R1 engine was completely reborn with all new designs for the crankshaft, crankcase, the head, the lubrication and cooling systems, as well as the intake and exhaust systems and reduction gear assembly. On the other hand, the important
performance parts like the cam shafts, intake/exhaust valves, valve springs. shims and cam covers were all kept the same as the parts on the original YZF-R1. The forged pistons and plated cylinders were also kept the same.
Rigidity analysis parameters and cast aluminum frame
In recent years, the trails snowmobiles are used on in North America are well maintained and market demand is for machines with excellent handling qualities to make the most of these trails. As soon as the first test model was built, the job of getting the right rigidity quotients for the frame began. “The snowmobile is a unique vehicle that runs on a combination of two skis and one track, so it requires a unique system of rigidity analysis in its design. At Yamaha we have adopted a unique analysis method for snowmobiles in which we set the front right and left suspensions in a fixed position and then apply weight to the rear portion of the rear suspension in order to measure basic torsional rigidity of the chassis. Taking this as the base, we conduct tests to see what kind of lateral sliding of the track occurs in actual running conditions and then work through trial and error to develop ideal performance,” says Mr. Nakano.
One of Mr. Nakaiio's Project Chiefs, Mr. Shinichi Nishijima, talks about how the RX-1 came to have handling performance that is different from snowmobiles of the past. “The development of the frame was not conducted from the standpoint of what a 4-stroke frame should be as opposed to a 2-stroke frame. Rather, it was undertaken as a separate step aimed at advancing to a whole new level of snowmobile handling,” he said. What his team built was not just a frame to carry a 4-stroke engine but one that takes handling itself to a new dimension. Their achievement can be seen in the fact that the RX- 1 boasts twice the torsional rigidity of the existing SXViper model.
The compact design of the engine was not without its own problems. The nature of the gas flow through the extremely compact crankcase of the RX-1 had an effect on lubrication, performance and fuel economy. It was too small of a case to enable normal flow analysis, so special see-through technology was employed. Using this method, repeated changes had to be made in its shape, a millimeter at a time, until the problem was solved.
The aluminum frame of the RX-1 registered a torsional rigidity value nearly twice that of the SRX’s, even though the total weight of the frame is less than the SRX’s. This was achieved by using different types of aluminum alloys to their best effect in different parts of the frame. Another key factor was the use of Yamaha-exclusive casting technology, which is also being used today in places like the suspension of the Porsche 911, in the chassis of Ferrari and Audi cars and in frames of flatscreen TVs. Jointly developed by Yamaha Motor and Hitachi Metals, this method is known as HV die-casting maintains very fine granulation in the aluminum structure and reduces impurities to produce an ideal cast, especially in thinner parts.
Yamaha’s First A-Arm Front Suspension and New Seat Shape
Because a 4-stroke engine means more sprung weight than a 2-stroke, greater efforts were made to optimize the balance of the handling. This fact became the key in achieving a completely new snowmobile experience.
“With the RX- 1 we created a separate test sled specifically for proceeding with the development of a double wishbone front suspension. That is one more proof of how much we concentrated on handling performance of this model. By adopting rear exhaust and also having the muffler facing the rear, we were able to gain the space necessary for a double wishbone design. Also, by optimizing the layout of the suspension links we were able to minimize the fluctuation in the angle of the skis with regard to the snow surface and thus achieve sharper handling,” adds another Project Chief, Mr. Takahiko Kubota.
In addition to these measures, the shock absorbers were increased in size from the SRX's 36 mm to 40 mm, and the stabilizers were given a simpler, more efficient structure that also reduced their weight dramatically to just 40% of those on the SRX.
One look at the new RX-1 reveals that the shape of the seat is one of the most distinctive of its exterior features. The way it rises up to the rear with a slim profile truly suggests that this machine is different from snowmobiles of the past.
“To keep overall weight down, we never considered adopting EXUP (Yamaha four-stroke exhaust valve technology). But a simple 4-into-1 exhaust configuration would leave the engine weak in the low- to mid-speed range with an inevitable torque valley. In order to get the kind of torque we wanted as well is high-speed performance, we adopted a 4-2-1-2 muffler configuration. What's more, it's a rear exhaust system that helps keep the front-end weight to a minimum.”
On a 2-stroke model the muffler is in the engine compartment, but in order to give the RX-1 its rear exhaust layout, innovative changes were made in the shape of the seat and its length increased. In conjunction with revisions made to the shape of the fuel tank, the new shape provides greater freedom of hip position for the rider.
Developing Performance to Fit the Market Environment
The RX-1's running performance was developed through tests using sophisticated data acquisition equipment and 3-axis gyro sensors. At the same time, joint tests were run repeatedly with the local staff in North America to hone the performance even more closely to the actual needs of that market environment.
“Still, there were things like the lateral “yaw” movement that couldn't be analyzed by the existing software, so we had to improvise, doing things like mounting the sled with a 20 kg (44 lb) weight in order to get readings. Also, in the case of a 2-stroke model the engine braking effect during deceleration works almost until the sled comes to a complete stop. With a 4-stroke using the same continuously variable transmission (CVT), however, the sheer strength of the pumping loss would cause the V-belt to loosen and the engine braking effect would then cut out in the middle of deceleration. To handle this we had to make special adjustments in the CVT settings. But, with a series of exacting measures like adjustments to the flyweights whose centrifugal force activates the pulley, we were able to get both a stable continuous engine breaking effect and sharp acceleration feeling,” said Mr. Toru Izumi.
Even though it was a project to build a 4-stroke snowmobile virtually from scratch, the work proceeded in this way at a relatively fast clip. “We owe the speed with which we were able to work to the vast store of simulation and test data that had been gathered in repeated tests over the years in Yamaha's previous 4-stroke snowmobile R&D efforts. Another big factor was that we did all the design work on 3D CAD from the beginning”, said Project Leader Nakano.
The new RX-1 that was developed in this way will be released for sale in the autumn of 2002. But what is this innovative new personal vehicle actually like to ride?
“I'm sure that most people will really be surprised to see how small the engine is for a 4-cylinder and how compact we have been able to make the sled. One of the first things people will discover when they start up the engine is its appealing 4-stroke sound that comes from our unique exhaust system design. Then, when you accelerate you'll discover its awesome power. The aggressive response you get when you accelerate from the mid-speed range is out of this world. And, the overall riding comfort is quite good.”
“You will find new enjoyment in riding this model with its exciting power more than ever before. There is also its light, nimble handling. Anyone who comes to our RX-1 with the preconception that a 4-stroke is heavy and has poor response are in for a big surprise,” said Project Leader Nakano, echoing the words of his Project Chiefs.
What the RX-1 promises is a snowmobiling experience that could not have been achieved by any sled built around a multi-purpose engine or an adapted automobile engine. Mr. Nakano and Project Chief Nishijima sum it up this way: “This development project has produced a machine that we feel is a big step into the exciting world of next-generation snowmobiling.”
THIS WAS JUST THE BEGING THE APEX SHOULD BE THE CREAM OF THE CROP
:ORC
.
YES IT IS
The Story Behind the Development of the 2003 Yamaha RX-1
On January 3, 2002, at their remote northern-Wisconsin test facility, Yamaha Motor unveiled to the press the radical 2003 RX-1 as a new flagship of its snowmobile product line. A completely new engine specification for snowmobiles was found in the Genesis Extreme four-stroke powerplant. This is mounted in a newly developed “Delta-box” chassis, a lightweight, high-rigidity aluminum frame packed full of Yamaha’s most advanced design technologies. The result is a new breed of supersport snowmobile that takes performance to an all-new dimension. Where did all of this technology come from? In the Spring of 1999, a team of engineers was brought together to resume work on a four-stroke snowmobile project that would become the 2003 RX-1. Separate teams were set up to handle engine design, chassis design, suspension design and drive system design. Each of these teams was appointed a project chief in charge of design and another in charge of running tests. The project seemed to be right on track with no major surprises……..
Snowmobile development project leader Takuji Nakano was just returning from a week of vacation, booting up his computer and checking e-mail for the first time. He couldn’t believe what he was reading. “Let’s develop our next snowmobile production model around the YZF-R1 engine!” Is this for real? He asked himself.
As of the week before it had been decided to go ahead with the development of a 4-stroke engine snowmobile and the initial design drawings were nearing completion, but they were not for an in-line four-cylinder engine like the R’1s. This meant a complete turnaround in the product concept, but top management had given it the final “Go” sign and the project was on. Yamaha was not only going to produce and sell the world’s first high-performance four-stroke snowmobile, but they were going for the ultimate high-mark by utilizing their dominant YZF-R1 technology. They had been researching and developing four-stroke powered snowmobiles for years, but they were waiting for the “right” time for such a vehicle. Could the North American snowmobile market finally be ready for such an assault?
New 4-Stroke Based on 20 Years of Research
After carefully researching the marketplace, Yamaha decided to go with the plan of developing a 4-stroke model that would bring a new level of excitement and quality to the snowmobiling experience. That meant not just fitting a 4-stroke engine into a conventional snowmobile body but developing a completely new kind of machine to define a new category; the “4-stroke snowmobile.” This would be more than simply powering an existing snowmobile with the R1 engine; it would fulfill a dream that had actually begun some 20 years before.
In Mr. Nakano's words, “This new model represents the realization of an entirely new type of snowmobile, born of the know-how gained from four 4-stroke snowmobile R&D projects over the course of 20 years and brought together around piece of raw material: the R1 engine. That is what you have in the RX- 1.”
Mr. Nakano tells us about that two-decade history. “Our first 4-stroke snowmobile R&D project dates back to 1979. That was followed by similar projects in 1990, '98 and '99. In the '79 project we worked around a prototype mounting the 2-cylinder engine from the GX400 motorcycle. From this we realized that we could indeed get a quieter, cleaner-running snowmobile, but it still left a lot to be desired in the area of acceleration. In the '90 project we used the engine from the FZR400 but were unable to clear our target performance goals in the areas of drive feeling and low-temperature starting. Then in '98 we started another R&D project, again using a sports model engine. But the final weight of 380 kg left serious fears that the performance as a sports machine would be spoiled.” So, once again plans for a production model were shelved.
The project that finally led to the development of the new RX-1 got its start in 1999. “At the start of the project we were working on the premise that we would be mounting a 2 or 3-cylinder power unit. But just as we had verified the direction the final product would take and had started to work with an eye on eventual production, we were suddenly told that the decision had been made to go with the 4-cylinder R1 engine. I have to admit I was more than a bit surprised at first,” recalls Nakano.
“At the same time the move inspired us; if we are going to develop a new machine, what better starting point than to build it around Yamaha's most advanced engine. I thought, here would be a great chance to use this engine's light weight and high performance to build an entirely new type of snowmobile that broke the mold and offered a completely new type of riding excitement and fun.”
Developing a compact, snowmobile-specific engine
The R1 engine could not be used for a snowmobile just as it was. The places and principles under which it would be run are quite different, not to mention the average temperatures of the use. The R1 has a 6-speed transmission but on a snowmobile it would be driving the sled's track through an automatic centrifugal V-belt transmission. It would also carry the disadvantage of being heavier than a 2-stroke. “In a straight comparison with a 700cc 2-stroke engine, the 1000cc 4-stroke is about 10 kg (22 lb) heavier. Our job was going to be to find a layout that would be as compact as possible and reduce the front-end weight as much as possible in order to get handling that was nimble and sporty,” says Mr. Nakano.
“We went through so much trial and error just to determine the best positioning for each axis; not only where the crank shaft and the drive shaft should be but also the cam shaft and the water pump, etc. There was even one proposal to put all three of the main axes, the crank, drive and clutch, on the same axis. Eventually we were able to reduce the engine height by 50 mm by giving it a dry sump lubrication system that requires no oil pan. And, we mounted it the reverse of how it sits on the R1 to bring the exhaust system to the rear. When we tried the idea of mounting the engine with a low center of gravity and as close to the center of the sled as possible, we realized we had found the ideal position,” he adds.
In this way, the R1 engine was completely reborn with all new designs for the crankshaft, crankcase, the head, the lubrication and cooling systems, as well as the intake and exhaust systems and reduction gear assembly. On the other hand, the important
performance parts like the cam shafts, intake/exhaust valves, valve springs. shims and cam covers were all kept the same as the parts on the original YZF-R1. The forged pistons and plated cylinders were also kept the same.
Rigidity analysis parameters and cast aluminum frame
In recent years, the trails snowmobiles are used on in North America are well maintained and market demand is for machines with excellent handling qualities to make the most of these trails. As soon as the first test model was built, the job of getting the right rigidity quotients for the frame began. “The snowmobile is a unique vehicle that runs on a combination of two skis and one track, so it requires a unique system of rigidity analysis in its design. At Yamaha we have adopted a unique analysis method for snowmobiles in which we set the front right and left suspensions in a fixed position and then apply weight to the rear portion of the rear suspension in order to measure basic torsional rigidity of the chassis. Taking this as the base, we conduct tests to see what kind of lateral sliding of the track occurs in actual running conditions and then work through trial and error to develop ideal performance,” says Mr. Nakano.
One of Mr. Nakaiio's Project Chiefs, Mr. Shinichi Nishijima, talks about how the RX-1 came to have handling performance that is different from snowmobiles of the past. “The development of the frame was not conducted from the standpoint of what a 4-stroke frame should be as opposed to a 2-stroke frame. Rather, it was undertaken as a separate step aimed at advancing to a whole new level of snowmobile handling,” he said. What his team built was not just a frame to carry a 4-stroke engine but one that takes handling itself to a new dimension. Their achievement can be seen in the fact that the RX- 1 boasts twice the torsional rigidity of the existing SXViper model.
The compact design of the engine was not without its own problems. The nature of the gas flow through the extremely compact crankcase of the RX-1 had an effect on lubrication, performance and fuel economy. It was too small of a case to enable normal flow analysis, so special see-through technology was employed. Using this method, repeated changes had to be made in its shape, a millimeter at a time, until the problem was solved.
The aluminum frame of the RX-1 registered a torsional rigidity value nearly twice that of the SRX’s, even though the total weight of the frame is less than the SRX’s. This was achieved by using different types of aluminum alloys to their best effect in different parts of the frame. Another key factor was the use of Yamaha-exclusive casting technology, which is also being used today in places like the suspension of the Porsche 911, in the chassis of Ferrari and Audi cars and in frames of flatscreen TVs. Jointly developed by Yamaha Motor and Hitachi Metals, this method is known as HV die-casting maintains very fine granulation in the aluminum structure and reduces impurities to produce an ideal cast, especially in thinner parts.
Yamaha’s First A-Arm Front Suspension and New Seat Shape
Because a 4-stroke engine means more sprung weight than a 2-stroke, greater efforts were made to optimize the balance of the handling. This fact became the key in achieving a completely new snowmobile experience.
“With the RX- 1 we created a separate test sled specifically for proceeding with the development of a double wishbone front suspension. That is one more proof of how much we concentrated on handling performance of this model. By adopting rear exhaust and also having the muffler facing the rear, we were able to gain the space necessary for a double wishbone design. Also, by optimizing the layout of the suspension links we were able to minimize the fluctuation in the angle of the skis with regard to the snow surface and thus achieve sharper handling,” adds another Project Chief, Mr. Takahiko Kubota.
In addition to these measures, the shock absorbers were increased in size from the SRX's 36 mm to 40 mm, and the stabilizers were given a simpler, more efficient structure that also reduced their weight dramatically to just 40% of those on the SRX.
One look at the new RX-1 reveals that the shape of the seat is one of the most distinctive of its exterior features. The way it rises up to the rear with a slim profile truly suggests that this machine is different from snowmobiles of the past.
“To keep overall weight down, we never considered adopting EXUP (Yamaha four-stroke exhaust valve technology). But a simple 4-into-1 exhaust configuration would leave the engine weak in the low- to mid-speed range with an inevitable torque valley. In order to get the kind of torque we wanted as well is high-speed performance, we adopted a 4-2-1-2 muffler configuration. What's more, it's a rear exhaust system that helps keep the front-end weight to a minimum.”
On a 2-stroke model the muffler is in the engine compartment, but in order to give the RX-1 its rear exhaust layout, innovative changes were made in the shape of the seat and its length increased. In conjunction with revisions made to the shape of the fuel tank, the new shape provides greater freedom of hip position for the rider.
Developing Performance to Fit the Market Environment
The RX-1's running performance was developed through tests using sophisticated data acquisition equipment and 3-axis gyro sensors. At the same time, joint tests were run repeatedly with the local staff in North America to hone the performance even more closely to the actual needs of that market environment.
“Still, there were things like the lateral “yaw” movement that couldn't be analyzed by the existing software, so we had to improvise, doing things like mounting the sled with a 20 kg (44 lb) weight in order to get readings. Also, in the case of a 2-stroke model the engine braking effect during deceleration works almost until the sled comes to a complete stop. With a 4-stroke using the same continuously variable transmission (CVT), however, the sheer strength of the pumping loss would cause the V-belt to loosen and the engine braking effect would then cut out in the middle of deceleration. To handle this we had to make special adjustments in the CVT settings. But, with a series of exacting measures like adjustments to the flyweights whose centrifugal force activates the pulley, we were able to get both a stable continuous engine breaking effect and sharp acceleration feeling,” said Mr. Toru Izumi.
Even though it was a project to build a 4-stroke snowmobile virtually from scratch, the work proceeded in this way at a relatively fast clip. “We owe the speed with which we were able to work to the vast store of simulation and test data that had been gathered in repeated tests over the years in Yamaha's previous 4-stroke snowmobile R&D efforts. Another big factor was that we did all the design work on 3D CAD from the beginning”, said Project Leader Nakano.
The new RX-1 that was developed in this way will be released for sale in the autumn of 2002. But what is this innovative new personal vehicle actually like to ride?
“I'm sure that most people will really be surprised to see how small the engine is for a 4-cylinder and how compact we have been able to make the sled. One of the first things people will discover when they start up the engine is its appealing 4-stroke sound that comes from our unique exhaust system design. Then, when you accelerate you'll discover its awesome power. The aggressive response you get when you accelerate from the mid-speed range is out of this world. And, the overall riding comfort is quite good.”
“You will find new enjoyment in riding this model with its exciting power more than ever before. There is also its light, nimble handling. Anyone who comes to our RX-1 with the preconception that a 4-stroke is heavy and has poor response are in for a big surprise,” said Project Leader Nakano, echoing the words of his Project Chiefs.
What the RX-1 promises is a snowmobiling experience that could not have been achieved by any sled built around a multi-purpose engine or an adapted automobile engine. Mr. Nakano and Project Chief Nishijima sum it up this way: “This development project has produced a machine that we feel is a big step into the exciting world of next-generation snowmobiling.”
THIS WAS JUST THE BEGING THE APEX SHOULD BE THE CREAM OF THE CROP
:ORC
well one of the main reasons y skidoo is leading sales bcuz 75% of their customers end up buying a second sled cuz their first one blew up so to complete the riding season they had to buy another one
Lets give Doo some credit here for getting to #1. They found a way to appeal to the masses and designed a completely new sled that has set the standard for big bump capability. That said, ill never go back to a 2 stroke again and if 4 strokes are the future of the sport, arent you glad you picked Yamaha?...BBY
snowmotion
Expert
Our RX1 Engine Uses Less Oil UNLESS you turn it upsde Down
Our RX1 Engine Uses Less Oil UNLESS you turn it upsde Down Then it Leaks like a sieve the fact that putting our sled on its side or rolling it over pours oil everwhere is an issue I would Like the Yamaha Engineers to Fix and retroactivly at that.
Our RX1 Engine Uses Less Oil UNLESS you turn it upsde Down Then it Leaks like a sieve the fact that putting our sled on its side or rolling it over pours oil everwhere is an issue I would Like the Yamaha Engineers to Fix and retroactivly at that.
Bakemono
TY 4 Stroke Guru
Have you seen the ad that Bombardier has for their Johnson/Evinrude outboard boat motors?
They basically claim that their SDI 2-strokes are cleaner, quieter, lighter, more powerfull, more fuel efficient and cheaper to operate in the long run that comparable 4-strokes.
Whatever. Im not a fan of 2-strokes. I recently upgraded from an Echo 2-stroke weedwacker to a Honda 4-stroke weedwacker. Let me tell you, I'll take a 4-stroke over a 2-stroke any day! That Honda is so much nicer to use than that Echo was.
The fewer 2-strokes I have in my garage, the better.
Cap'n
They basically claim that their SDI 2-strokes are cleaner, quieter, lighter, more powerfull, more fuel efficient and cheaper to operate in the long run that comparable 4-strokes.
Whatever. Im not a fan of 2-strokes. I recently upgraded from an Echo 2-stroke weedwacker to a Honda 4-stroke weedwacker. Let me tell you, I'll take a 4-stroke over a 2-stroke any day! That Honda is so much nicer to use than that Echo was.
The fewer 2-strokes I have in my garage, the better.
Cap'n
sobfrogg
TY 4 Stroke Guru
Hey Captain,
The Honda weed wackers are nice, but???????
Keep an eye on the cam at the top of the head. They are known to wear out. When you put oil in the engine make sure th oil comes up to the top of the dipstick hole.
The engine only holds about 2.8oz of oil. HAVE FUN WHACKING
The Honda weed wackers are nice, but???????
Keep an eye on the cam at the top of the head. They are known to wear out. When you put oil in the engine make sure th oil comes up to the top of the dipstick hole.
The engine only holds about 2.8oz of oil. HAVE FUN WHACKING
i hate that bombardier ad (i gusse ur talking about that 1/2 hour long one)
they were also racing 2-stroke to 4-stroke and when it comes to the water an 2 and 4-stroke of equal Hp the 2-stroke will still always turn out on top, it isn't fair
although from now on its four-strokes for me , lets see em' race a yamie V-max or something like that 
they were also racing 2-stroke to 4-stroke and when it comes to the water an 2 and 4-stroke of equal Hp the 2-stroke will still always turn out on top, it isn't fair
although from now on its four-strokes for me
, lets see em' race a yamie V-max or something like that 
LazyBastard
TY 4 Stroke God
I find that it doesn't matter if an engine is 2 or 4-stroke. There are good 2-strokes, bad 2-strokes, good 4-strokes, and bad 4-strokes. Take the good and I'm happy. I think I'll keep my Vmax175. Its happy with one gallon of cheap ($15) oil per year and goes further on the same gas than my truck. And its quiet and smooth enough to have a conversation with the skier out behind.
Pureadrenaline
Expert
rx-1erlimitededition
Extreme
This advertisement, has to be without question, the worse piece of crap to ever come out of any snowmobile manufacture. It even out tops the Polaris BS that was put out as they share was sinking out of sight. Pitiful, Pitiful, Pitiful. Try using the fuel calculator and you can't win! If you get twice the mileage of the doo it says they are comparable. I would have expected this bull from Poo or Cat, but not from the market leader. Is this the sign of another number 1 share leader, that is sinking and feels they can trick the knowledgable buyer? Sad, very very sad!!!!!!!!!!!!!!!!!!!1
LazyBastard
TY 4 Stroke God
There is a history of tricking the consumer in the snowmobile market. The whole 2-cyl thing is the best example.
EVERYONE who knows anything about engines knows that 3 cyl is better than 2... Strictly from a fuel economy perspective, or from a RELIABILITY perspective, comfort, POWER, etc., but they fooled a LOT of consumers into stepping backwards into twin when the WHOLE PURPOSE of the move from 3 back to 2 was to REDUCE COSTS.
EVERYONE who knows anything about engines knows that 3 cyl is better than 2... Strictly from a fuel economy perspective, or from a RELIABILITY perspective, comfort, POWER, etc., but they fooled a LOT of consumers into stepping backwards into twin when the WHOLE PURPOSE of the move from 3 back to 2 was to REDUCE COSTS.
LazyBastard
TY 4 Stroke God
It didn't reduce weight.
More cylinders, but MUCH LARGER. Shorter crankshaft, but FATTER. Ever look under the hood of a vmax600-triple vs a vmax600-twin? The twin has two great big fat jugs, the tripple has three slender small ones.
More cylinders, but MUCH LARGER. Shorter crankshaft, but FATTER. Ever look under the hood of a vmax600-triple vs a vmax600-twin? The twin has two great big fat jugs, the tripple has three slender small ones.
I forgot they made so small tripple's... 
Try to compare a A-C 800 Tripple to a 800 twin! Or a Rotax 809 tripple to a Rotax 793 twin! The smaller tripple's will of course have much less difference than the bigger tripples. The only more compareable twin's to tripple's are the SDI-engines, much heavier then the carb'ed twin's, but still a little lighter then the old tripple's.
Try to compare a A-C 800 Tripple to a 800 twin! Or a Rotax 809 tripple to a Rotax 793 twin! The smaller tripple's will of course have much less difference than the bigger tripples. The only more compareable twin's to tripple's are the SDI-engines, much heavier then the carb'ed twin's, but still a little lighter then the old tripple's.
SledFreak
TY 4 Stroke God
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I believe the torque may have been an issue. A 600 twin would produce more torque than a 600 tripple in stock form.
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