The first dirt bike I ever owned was a TTR 125. While I was doing the research to find the perfect beginner dirt bike I found myself asking the question: is a Yamaha TTR 125 a 2 stroke or a 4 stroke dirt bike?
I’ve owned a TTR 125 since 2007 and it’s one of the best beginner trail bikes out there because it is a 4 stroke dirt bike. It’s nice and quiet which makes it perfect for hunting (that’s what I use it for) and also for teenage riders. If you’re looking for a great trail riding bike this could be it. However, Yamaha does make 125cc 2 stroke dirt bikes (the YZ series) and that is more for track riding.
That’s why it really depends on what you’ll be using the dirt bike for. Is it going to be used mostly on the track? Or is it something that will spend most of its time in the back bush?
I don’t ride on a track and that’s why I’ve always had 4 stroke bikes. The 2 strokes are way too loud and there’s really no reason to have one if you’re not racing.
Difference Between A 2 Stroke And 4 Stroke Dirt Bike?
I’ll start off by saying I’m not a mechanic and I don’t fully understand how an entire engine works. I know the basics and I’ll try to make things as easy as possible to understand. Sound good? Great.
2 Stroke Engines
These bikes are lighter, faster, and will kick harder than a 4 stroke bike. This makes them more difficult to ride and control because they do have that much more power.
The 2 stroke engine’s job is to focus on compression and combustion. They are generally easier to work on and the parts are cheaper as well. The downside? You’ll also have to work on them more often.
4 Stroke Engines
These bikes are heavier and slower but the good thing about them is that they are easier to control and ride. They are a bit more expensive to repair but you’ll have to do a lot less maintenance on them.
The engine’s job is to focus on intake, compression, combustion, and exhaust. Since there are more parts on a 4 stroke bike you’ll spend less time braking and shifting.
Do 2 Strokes Have More Power Than 4 Strokes?
The short answer to this is yes.
Since a 2 stroke engine will fire each time the crankshaft turns, it’ll produce a more powerful and less predictable kick. It’s also lighter and the combo of the two is what gives the bike higher top speeds.
The 4 stroke engine will fire every time the crankshaft turns twice and that’s what gives it a less powerful and more predictable kick. That’s the reason a 4 stroke dirt bike would make a better beginner bike for someone.
So if you were to compare a 2 stroke 125cc bike to a 4 stroke 125cc bike, the 2 stroke bike will win all day long. It’s not always perfect but usually, a 125cc 2 stroke will be similar to a 250cc 4 stroke.
Is A 250 4 Stroke Or A 125 2 Stroke Faster?
This is kind of an unfair question because if you were racing on a track it would all depend on the rider. The more experienced rider would win on either bike so it doesn’t really matter.
In my opinion, this is where I stand. If you’re a beginner rider you’ll probably be faster on a 4 stroke dirt bike. If you’re an experienced racer who can control your bike the 2 stroke bike would probably do you better.
A 2 stroke will get off the line much quicker but a 4 stroke will have better lower end power and is also more forgiving.
Yamaha TTR 125 Horsepower
It all depends on the year of the bike and whether or not it’s completely stock. On average, a stock TTR 125 will have around 7-8 horsepower (I haven’t tested this but it’s the consensus around the internet).
As for the top speed of a TTR 125, it’ll all depend on the weight of the rider. I’m heavier than a 12-year-old kid which will allow them to go faster. But a rough top speed on the bike would be 45-55 MPH.
There are lots of different things you can do to your bike to increase the horsepower. I haven’t done anything myself because I don’t need much power and rarely max it out (I’m using it for hunting and going through the thick bush).
People have said they were able to double that number which would make a big difference but I don’t know if that’s completely true or how good it was for the bike. Sometimes you can do things to engines that’ll improve power but often times it messes up the engine.
Then again, it is mainly a bike for teenagers and I don’t really know if parents want the thing to go faster.
What Does TTR 125 Mean?
Let’s start with the TTR part. Back in the day, Yamaha had a model called TT which I believe stands for trail. They were big, heavy bikes that were made for trail riding (who would have guessed?).
The R stands for racing. The newer TTR models share some of the same parts as the YZ and YZF bikes which makes them lighter and easier to ride.
Now the 125 part. A 125cc dirt bike means it has a 125 cubic centimeter cylinder block (volume). When the cubic centimeter of the bike increases it’ll allow more air/fuel in and will result in more power.
Again, I’m not a scientist but that’s how I understand it. Feel free to correct me.
Let me know your thoughts and any questions you have. Like this article? Feel free to give it a share!
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