so today I wanted to do a few words on basically two-stroke vs. four-stroke power right and I know this is a hotly debated topic and I'm and I'm here to tell you that two strokes are not better than four strokes and four strokes are not better than two strokes in my opinion they they are just different tools for different jobs and beyond that they are also just different flavors to suit people's preferences and so the 30-second summary of this video is that they are both awesome and you should probably own a two-stroke and four-stroke at least at some point but beyond that what this video is about is to look at some technical data on the differences between two strokes and four strokes and specifically looking at motor output which is effectively the biggest component of two-stroke and four-stroke signatures so we're gonna jump into power and torque curves and I'm gonna try to make it as non-technical as possible and just really try to share what the different characteristics of each bike is and what makes each bike amazing and unique in their own way so let's jump right into it we're gonna look at power and torque curbs primarily and our first first chart here is a is a awesome graphic provided by JD jetting and if you don't know who JD jetting is or what they do you should definitely check them out they make awesome products I'm a you know I'm a customer of JD Jenning and I've been very happy with their products we're going to use their information just because the two charts that I'm going to show you are probably the most descriptive charts or collection of data on two strokes and four strokes that I think exist on the web and we're gonna really look at these two charts and we're gonna really dissect the differences between between the six bikes shown and what's great about these two charts is they focus on one brand which is KTM and they focus on the three most popular two-stroke models or I should say displacements in the three most popular four-stroke displacements and yeah with this landscape of bikes you get a huge range of just characteristics of motorcycles and I just love this data and I wanted to share the way I interpret this data with you know with people to help them understand really the differences between all six bikes and why all six bikes are really awesome so okay let's get started so I think a good place to start is just to look at overall power of each model and so what is power well power is measured in horsepower and so what is horsepower horsepower is just a force multiplied times a rotational velocity right so in this case its torque times rpm so to make things relatively simple right horsepower is just the amount of torque multiplied by constant multiplied by an RPM so by that definition or by that equation if you have a motor that reps higher it will always produce more horsepower okay you could have two motors that produce the same power with one motor producing very little torque and spinning really quickly or with another motor producing a lot of torque and spinning very slowly so power although it's a good indicator of you know what you can get out of a motor it's it's not fully descriptive it doesn't tell the whole story because you're combining two very important variables right in in one into one number so that's where we want to look at both output power but we also want to look at torque curves so keeping in mind power only tells part of the story let's look at two really common bikes a KTM 302 stroke and a KTM 450 four-stroke here you can see they produce basically the same amount of power at basically the same rpms we look at a 250 two-stroke and a 250 four-stroke this is where things get really interesting right so 250 two-stroke makes 48 horsepower right under 9,000 rpm and at 250 four-stroke makes thirty-eight horsepower all the way at 13,000 rpm so this is a great example what I mean by that is our PM's take time to build and in in similar engines like dirt bike engines regardless of their two strokes or four strokes it's going to take longer it's going to take more time to get to 13,000 rpm than it is to 9,000 rpm so that 250 two-stroke making 48 horsepower at 9,000 rpm is going to happen much faster it's gonna happen much sooner than that 250 four-stroke making its max power at 38 horsepower at 13,000 rpm that's why the 250 two-stroke basically hits you in the face and it hits super hard verses a 250 four-stroke not only does a 250 two-stroke make more power but it makes it way more aggressively and way faster way lower in the RPM range now let's add the 350 four-stroke to the mix you can see the 350 four-stroke makes 45 horsepower slightly less than a two-stroke 250 and it makes it a little over 10,000 rpm so yeah that makes sense I mean the 350 four-stroke is not as powerful as a 250 two-stroke and it makes it more it makes the power more gradually and it holds that power pretty flat at a pretty large rpm range which makes it 350 really produce really usable power now let's compare a 350 four-stroke to a 450 four-stroke the 454 stroke makes 52 horsepower at 9,000 rpm and the 350 four-stroke makes 45 horsepower at slightly over 10,000 rpm simply put the 450 makes more power much faster than the 354 stroke and well that's what it feels like for now let's not worry about the 200 XE it clearly makes the least amount of power now to get a deeper understanding of power and how that power develops in an engine let's split up this chart into three sections low mid and high low rpms mid rpms and high rpms generally you can think of low rpms as low speed riding mid rpms as where usually where you want to be when your trail riding and high rpms when you're really moving that's not exactly accurate but that's a generalization and you can think of it that way if you look at the low end nothing too exciting is happening the smaller bikes the 200 and then 250 are pretty low and the bigger bikes are higher and the 350 is just in the middle what's interesting is that the 250 four-stroke is well significantly lower than 200 XC the mid-range is where things get really interesting you can see all three two strokes hit their maximum power right under 9,000 rpm basically at the same time what's also interesting is the 450 also hits its max power right about 9,000 rpm just a little bit higher than the 300 XC the other four strokes however they don't hit their high power till way higher in their rpm range the high rpms are where the four strokes really shine the two strokes well they're done they're totally cooked dr. 10,000 rpm at high rpms the four strokes keep chugging along the 450 continues to make good power all the way to 11,500 the 350 sings along well all the way to past 13,000 with a really nice flat spot between 9,000 and 11000 rpm and then begins to sign off after 11,000 all the way to 13,000 now the 250 four-stroke well it just keeps building power it just keeps building power all the way to almost 14,000 RPM with a really nice flat spot between 11,000 RPM and 13,000 RPM this is where this motor really shines you have a lot of usable power with a really broad range of rpms but you have to get way up there in the RPM range to take advantage of that now the 350 the 350 is pretty magical I mean it does sign off after eleven thousand rpm it does start to decrease in power but it has a huge flat usable power range from the mid range all the way to high rpms from I don't know 8500 rpm all the way to 11000 rpm the power really doesn't change a whole lot that's what makes that bike so writable now that we've looked at power at individual rpms let's look at the entire power curve let's look at the area under each power curve and see what that tells us about each bike here's the entire area of the power curve for a 250 four-stroke you can see it builds power very gradually and has a huge usable rpm range from 3500 rpm all the way to red line at almost 14,000 RPM this bike is nice and easy to ride build power gradually and doesn't really surprise you at any point in the power curve here's the power curve for a 250 two-stroke it creates a huge surge of power from 4000 rpm all the way to 8500 rpm and then signs off after 10000 rpm basically it's a huge linear pool of power that happens very quickly and then it and then dies off just as quickly here the power curves for a 250 four-stroke and a 250 two-stroke overlayed I love this graphic this basically shows the difference between a two-stroke and a four-stroke same displacements completely different characters the 250 two-stroke builds power quickly aggressively and then signs off where the 250 four-stroke builds power gently and doesn't sign off to way higher on the RPM range basically a 250 four-stroke has to be ridden hard and all the way in the upper rpm ranges from 11,000 to 13,000 rpms to get the most power out of it or as a 250 two-stroke just punches you in the face and creates power immediately and very sharply let's add the 350 into the mix the 350 almost matches the 250 two-strokes power but not quite however it really stretches out the power band well into the high rpm ranges better yet it basically stays flat and power from 8,500 rpm all the way into 11000 rpm which gives you a really nice usable band of power what this graphic shows is that the 354 stroke really is the middle ground between a hard-hitting aggressive bike and a much more mild civilized bike like the 250 four-stroke now let's look at a 250 two-stroke and a 302 stroke if you were to look at the power bands of both these bikes you would think that the 300 two-stroke outperforms a 250 all the way across the power band and technically it does you can see from this graphic the 300 two-stroke power band overlay is the entirety of the 250 two-stroke power band all the way across all the par PM range what this graphic doesn't show you and what no power band graphic will show you is how quickly a motor revs to a certain rpm this is where the 250 is very exciting it almost matches the power output of a 302 stroke but it wraps so much faster than a 300 two-stroke because of a lighter piston this is what makes a 250 two-stroke one of my favorite bikes let's look at these power bands a little closer specifically the 300 two-stroke the 300 two-stroke is arguably one of the most popular trail bikes ever made it creates an awesome hit of power that's very linear and then dies off relatively quickly if you look closely at 300 almost matches the 458 four strokes power band well at least to about 9,000 rpm then the 450 really continues to pull hard where the 300 just dies off and in reality for trail riding you don't need those extra rpms those extra rpms for the 454 stroke they pay off at high speed and on the motocross track but in the trail and in the gnarly the 300 well it's really all you need now let's add the 202 stroke the 202 stroke well it just makes less power but what's not great is it doesn't make the power in such a linear fashion as the 300 and it has a little burp of power right at 7,000 rpms that carries all the way to red line what this graphic doesn't show is that the 200 revs really quickly just like the 250 revs faster than 300 the 200 revs faster than 250 and it creates this surge of power super aggressively super quickly which makes a bike really fun to ride and that makes a bike have a very unique character so don't discount the 200 it's pretty awesome it's just not a 300 it's just different now that we've looked at power let's look just at work remember torque is just a component of power right you can think of torque as the amount of force your rear tire is putting onto the dirt at a certain motor rpm it's not really that simple but that's just a way to think about it to work is super useful to get you up in over obstacles and to just get you to accelerate quickly in many situations torque is more important than horsepower first let's look at overall torque figures in red are the two strokes and in blue are the four strokes let's start with a 300 X C it's arguably the king of torque as it makes the most torque right off idle at 4000 rpm and it carries strong torque all the way to its max at 33 it beats every bike and how much torque it makes however interestingly enough the 450 makes almost as much torque and it makes it sooner in addition it has a much smoother torque curve than the 300 X C and it carries torque well after the 300 is signed off that's interesting because the 450 isn't really known as a bike that's good for the gnarly well there's other reasons for that the 350 four-stroke well it's just stuck in the middle again it makes really good torque and it makes it for a huge range of rpm it doesn't produce any kind of crazy torque figures but it does in a very consistent way on its way up and on its way down the 200 XE hands down beats the 250 s X and torque it makes more torque all the way across its usable rpm range and you could argue it makes it in a more consistent manner now here is an unfair comparison look at the 300 X C and look at the 250s X F the 300 C is known as a bike that excels in the gnarly where low rpms low speed and a lot of torque is needed and then 250 SX well it really shines and flowy open trails well if you look closely you can see the 300 X C makes more torque right off idle and then 250 SXF ever makes through its entire rpm range doesn't matter how much you read the 250 SX it basically never makes more torque and that 300 X C does right off idle now let's look at one of my favorite the 250 two-stroke the 250 two-stroke is basically a baby 300 except it revs a lot quicker and it's a lot more involving to ride you can get the same out of a 250 as you can have 300 you just have to ride it harder and rev it a lot more well there you go guys my two-stroke vs. four-stroke video keep in mind both bikes are awesome you can't go wrong with either they're just different if you can own both I would strongly suggest it you will get better by writing both bikes and learning the subtleties of each type of bike the two-stroke will teach you something before stroke can't and same thing with a four-stroke you learn something on the four-stroke that there's no way the two-stroke will teach you thanks for watching guys if you like this video please subscribe and hit that notification button
