4 stroke vs 2 stroke

[RowdyYates]

I am going to buy a used dirt bike shortly and I have owned only Honda's in the past ( CR 125 and CR250). It will be used for trail riding only. I have heard these newer 4 strokes are high maintenance. I was looking into the Honda CRF 450R or 450X. I have heard they are constant maintenance on the valves. I like the fact the Honda has separate oil for engine and tranny, Some say this is their downfall for engine problems because the engine has smaller oil volume. Any one actually own one of these and let me know your opinion on the overall bike? I would also like input on the newer 2 stroke mainly 300 KTM. I understand they are geared for trail riding and you can lug them down. Thank u

 

[Robenstein]

Most everyone I know around here that rides for fun has a Yamaha or Suzuki. The dual sport Suzuki bikes have a good reputation for endurance. I know a guy that does iron butt rides and took a Suzuki DR through Mexico, Central, and South America and back twice with no issues other than flat tires and oil changes.

 

[Spazdog]

For playbike duty, there are really only two left that would be durable and easy to maintain. The CRF230 and TT230. If you are used to a CR250, you are going to find the CRF230 woefully inadequate. Both also have electric start which seems unnecessary. I had an XR 200 that was very easy to kick. Also an XL185 that was ridiculously easy to kick. I loved my XR200 (the two valver. not the radial 4 valver) Once outfitted with bigger XR forks and rear shock, I could ride it 10/10ths all day and it wouldn't break. It sipped gas at half the rate of the 125 2 strokes but once in a straight, they would walk away from me and I couldn't do a thing about it.

 

[ccdhowell]

I race quads in a series that has both bikes and quads, hence I know lots of bike guys. At the races there are still many 2-strokes but all of my friends ride 4-stroke bikes. The picture you portray of valve maintenance may be overblown, on my quads, I check and adjust my valves 4 times a year, usually after every two races. They are usually tight, but not crazy tight, but we run the mess out of these engines 90 minutes at a time. The newer 4-stroke engines are tough, IMO, to adjust the valves on. The Honda, Yamaha, Suzuki and Kawasaki engines require shims between the top of the valve and the lifter. It is a bit of a pain because you have to remove the cams to adjust the valves, with all that entails. I also have a KTM 4-stroke 450, it is much easier to adjust, no shims, just turn a screw on the rocker arm and tighten the lock nut. A word of caution about 450 dirt bikes...they are not for the timid or inexperienced rider. Not to sound too cautionary, but I know plenty of experienced cross country racers who stay on 250 4-strokes because 450s are too much to handle safely and quickly. They say you have to stay on top of the bike too much, you can never relax and enjoy the ride. That's just hearsay, I have no personal experience with bikes at all, I'm a quad guy and we all ride 450s, but there is a sizable weight difference to consider. Hope I helped.

 

[RC46_Rider]

Short version: Yes, the new 4 strokes are high maintenance. Adjustments are critical and you need to be moderately skilled or expect to pay a dealer. If the bike is TRULY not run in a race mode, they will definitely go a lot farther between maintenance, but the new full on racing 4 strokes push it hard....thus the higher frequency oil changes, etc. They are a blast to ride and most people think they are easier (especially in trail riding) to ride than a 2 stroke, but the price to pay for the performance is $$$. Be REALLY sure you want or need a 450. The previous comments about them NOT being "fun" is true unless you are very skilled; it is, in fact, difficult to "relax" when that kind of power is connected to the throttle, especially, the MX bikes; they are full out racing machines: Period. The power, throttle response and speed is not forgiving. They are also heavier, which is not so good in "technical" stuff...a surprising number of guys around here went back to 250's due to the weight difference. My son races Hare Scrambles off road and still prefers a 2 stroke due to the lighter weight and throttle response....but for trail riding, depending on how challenging the terrain is, a 4 stroke more forgiving. Do your homework on the bikes... I would look hard at KTM's off road models and the new Huskies are seemingly decent. If you want an MX bike, you have lots of good options. The downside to the MX bikes is that they are geared higher, have peaky power bands and stiffer suspension which can beat you up on a long, all day ride. In an off road situation they can be very hard on clutches in slower, tight sections. I had a KTM 200EXC for quite a while and it was amazing....light and had a stunning amount of power and low end grunt for what it was. That KTM300 has a ton of low end torque if you like a "tractor" but it will also fly if needed. Good luck.....

 

[AVB]

KTM probably makes the best stock trail bike. I have hear lots of good things about the 200. I had a riding buddy that had a 98 KTM 250EXC. Some of the KTMs come with a flywheel weight standard and aftermarket flywheel weights are available for most 2 stroke mx bikes. The weight helps soften the hit and also makes the bike harder to stall. I am happy with my 02 CR250R the only things I have changed are the silencer, added radiator supports, a skid plate, and when I replaced the chain and sprockets I went with a bigger rear sprocket. I actually only geared it down for more punch on the track. The trails we ride follow a river and get really slick when it rains, there are a lot of technical sections with rocks, ditches, tree roots and enbankments. Sometimes the 52hp of the CR250 come in handy when trying to clear obstacles. A lot of people talk about spark plug fouling with two strokes, that has not been my experience at all. The only times I have had to change a spark plug was in wet conditions when crossing foot deep water holes.

 

[Mik]

I have a friend/acquaintance in Alberta who has been riding for decades and still competes in various types of off-road events. He had been riding 450 cammers as most do now (so little else to choose from with the quasi-disappearance of two-strokes) but bought a KTM 300 a little while back. He has been, and remains, totally and utterly impressed with the bike. He stated that it is superior to the cammers in every way and has now sold his 450. Take it for what it's worth but he has made it sound to me like there is no real choice in the matter, the Katoom 300 is the top dog (not only in all-out performance, but in ease of riding)

 

[sunruh]

rowdy, for all of the 4strk info you could ever want, please go to www.thumpertalk.com and have a look. it is the worlds largest 4stroke dirtbike forum. lots of varied info from above. i have 1 suggestion: ride as many bikes as you can before you buy. steve

 

[Cujet]

The "ultra" performance 4 strokes can be expensive and time consuming to maintain, especially the smaller ones. However, the larger ones (such as the 450's you listed) do last quite a while before failure, often over 150 hours of play riding. I love the big bore 4 stroke power, all you could ever want, just when you want it. However, it's difficult to beat the power to weight of a 2 stroke. And, that is why I ride a KTM 380 EXC, with a (minimalist) street legal kit! The Honda CRF450X is competitive with my bike, but is heavy enough to be a real handful in the Florida sugar sand. The specs show my bike at 218 pounds dry and 240 full tank. I weighed mine at 238 in current form, fully loaded. The CRF450X is North of 270 pounds in real world tests. If you don't ride in soft sand, the weight won't matter nearly as much. Obviously, the motocross version is lighter. Edit: I neglected to add that the Yamaha WR450 is known to be a very reliable and long lasting engine. Even for street use and even with many mods. They are quite good. One reason may be the 5 valve setup. As the valves are slightly smaller and don't have as much inertia at high revs. Therefore they don't pound the seats as badly. Here is a pic of my 380. I've fixed it up quite a bit since then (that was the day I purchased it)