Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: KX125rider on May 27, 2010, 03:23:25 PM
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so last week I was able to woods ride an rmz for a day. here are my observations-
the bike I normally ride is a 98 kx125 for reference
this bike feels like it pulls the same from idle to limiter
actually feels slower than the 125 on the top (probably is faster)
it made me a lazy rider- riding trail in 3rd at 1/4 throttle rather than screaming 1st and 2nd
it handles amazing- modern chassis
feels much heavier in the turns
much easier to jump
not terribly loud (drd with sparky insert
ive never tried a 250 2 stroke but im sure it would be more exciting.
so anyway who has actually ridden a 4 stroke? or is everything said about 4 strokes come from what has been read or what your friends have told you?
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I haven't had a chance to ride one yet. A friend of mine just bought a 2010 KX250F and hopefully I'll get to ride it soon. I really have nothing against 4 strokes and think the new ones are mechanical marvels, my issues are with the AMA, the manufacturers and the media.
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I have never ridden a four stroke, to me the sport of motocross is a pure thing, the two stroke engine is a pure thing incomparison to a four stroke.I've spent over twenty years working on the worlds most exotic and complex automobiles.
So when I think about all the technology that could come to bear on my pure sport it makes me cringe a little,I will bet before we change the tide we will see a few things like variable cam timming as well as variable intake runners come to be. If they refuse to give it up all dirt bikes will eventually become diesels. IT IS THE NEXT LOGICAL STEP. I have nothing against four strokes but, motocross and off roading have very few rules.....PURE......SIMPLE...KEEP IT THAT WAY
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I have ridden both two-strokes and four-strokes... the four-strokes can be fun under certain circumstances. They are so easy to ride and do inspire confidence. The one place I felt really uncomfortable was in turns, they don't want to turn so easy... usually you end up searching for something to bounce off of..
I think everyone should at least try one... interesting bikes.
The only way they are competitive with two-strokes is because they are bigger. At equal displacement the four-strokes would be in a museum!
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I rode a friends race prepared KXF250 a couple of years ago and found while it was nice you had to rev the shit out of it.
If i wanted to do that i would rather have a 125.
The changing of lines was also harder than on a smoker.
I found i was quicker on my RM250 because i could use the mid range torque to my advantage.
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Yeah taking one for a ride is all well and good, but owning one is an other story >:(
I agree with G-Money,
who really needs a "high tech" 4 stroke engine so you can go riding around a dirt track with your mullet blowing in the breeze? it just doesnt make any sense
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What have you got against mullet's scotty ? ;)
Some of my best years were back in the day wearing that great fashion icon.
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I have tried a few, quite boring really.
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Even Joe is a bike fan.
(http://i864.photobucket.com/albums/ab207/tmkiwi/images.jpg)
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I keep telling my friend that when he has to rebuild his engine that I'll just buy his frame and stick my 490 engine in it ;D oh yeah, he paid over 6k for it ( cycle shop financed it for him )
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Hmmm, not the answers I expected to read, but interesting nontheless. I was riding and racing 250 four strokes four a couple of years. For sure they are easier to go fast on, hook up better out of slippery turns, put power to the ground through rough sections, track straighter into rough turns, and are easier to ride motos out on, as I found I could put in consistent lap times easier at the back end of a moto. I also suffered some huge crashes and some gnarly injuries, and was also a consequence of the heavier four stroke. I am stoked that I switched back to a two stroke. I am currently riding an 09 YZ 250, and still working on set up, but already stoked with how good it is. I was working on finishing long motos out strong on the two banger until I broke my leg a couple of weeks ago. One thing that I did notice fairly quickly was that you can actually ride out of big swaps everytime you get a bit loose, instead of being driven into the ground by the four stroke. On that last ride before I busted my leg, I had a huge moment through a big set of rolling whoops and was about to eject, but held on tight with my legs, leant back, held it wide and came out the other side. Couldn't believe it actually. Similar moments on the four stroke would have had me doing cartwheels and probably buying another new helmet. Just before I switched back to a two stroke I was riding my YZ250f and questioning why I still rode. It wasnt fun, scary at times, and I just wasnt enjoying riding anymore. I am so glad that I did what more and more guys are doing now and switched back to a two stroke. Now I just gotta get this cast off so I can go riding again. Cant wait.
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i like both have rode both and will probably buy both.
heck its a dirt bike they are all fun in some way.
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I've ridden both, worked on both, but have never owned a modern 4S, only modern XR 4 strokes. I've tried the CRF, YZF,WRF's 250's and 450's. The 2504S to me need to be reved out like a 125. The 250 and 450F's feel heavy to me. The CRF's headshake was a little scary, no wonder they put dampers on the new ones. And being a tuner I can't stand listening to all that 4S engine clatter. I tried a modified YZF250 and had to come in after two laps because my ears were ringing from the exhaust noise.
Some of the 4S repairs I've done includes complete rebuilds. I don't have to get into it too much to say, after rebuilding a modern 4S engine I will never own one. There is not a better Motocross engine cc for cc than a two stroke.
Also, I don't get why everyone keeps talking about this updated R+D in these new bikes. They don't seem to handle any better than some of the 90's bikes I've owned or ridden. Paul
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I don't MX race, never have never will. I own an old yz250 and have ridden more modern cr250r and an old yz490 plus several as a kid but don't remember models. I've had the older reliable 4 strokes, xt250 xr600r and have ridden others of this type. I can honestly say the 2 strokes have always been more fun, a power stroke every time the piston comes up top. The 4 strokes have always been lazy bikes to me but that works for trail riding too, power stroke every other time the piston comes up top.
For the joy riding I do, both work but without question the 2 stroker is way more fun. I'm sure the modern 250f & 450f's are fun to ride, but with them being built for hi performance the reliability is down the toilet and no way am I prepared to fork out money hand over fist to joy ride.
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I rode a 2004 and 2006 YZF250 and a 2006 KTM 525 and a YZF426. 4 strokes are weird, I mean typical 4 stroke if you shift into another gear without using the clutch you slow down when you let off the gas, automatic brakes. I could never tell what gear I was in because of that slow down effect (i was slowing down between every gear the fist time I rode one and wondering if I actually shifted or not?). That's a nit and prolly get used to once you become a four dope but I wasn't used to it.
The 250F I opened it up 5th gear full throttle on a short straight away, its probably like 3rd full open or a little under on my 83 maico 490, so guessing like 60mph.
Suspension is good I guess, good as any newer bike's, I mean it has nothing to do with the engine there's no springs in the transmission that are making it take the bumps easier so talk about suspenion is a non-starter because you can put the same shit on a 2 stroke. Sorry but nothing turns as good as my maicos for some reason, any newer bike I rode included. Of course I just rode the trails I didnt do 60 foot triples or race national mx with any of these bikes. Turned better than my older non-maicos tho, but that's not hard to do i.e. the KTM 495 doesn't turn it might as well be locked in straight and the turning radius is like 5 degrees. The CR500 the same thing, try to turn and it just want to go down instead.
The main draw back though is that those things may be quiet at idle so everyone is always saying 4 strokes are so quiet compared to 2 strokes, because at idle 2 strokes are loud. However, 2 strokes essentially don't get much louder from idle to top rpm, its only a small fraction. 4 strokes however have this wide range, they go from very quiet to breaking your ear drums. I've stood next to a 4 stroke that revved up, you can litterally feel your ear drum hurting. 2 strokes are loud but they aren't deep bass, it's more treble, that deep boom is damn loud once those things hit rpm when you revv them. It's so loud as to make you immediately annoyed. 2 stroke is loud but doesn't make you physically sick if you stand next to it when it revvs up.
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i have owned 4 strokes since when i was on 80s. nothing against them. for me the 2 stroke has brought the fun back into racing again. i still race a 4 stroke but i also take advantage of ama's rule of 250 2 stroke in the 250 class. if it wasnt for that rule i would probably still be trying to race a 250f. not easy as i am 190 pounds.
the injury thing kinda confuses me though. i cant get it through my head on how a 4 stroke causes more injuries. they might be heavier but they are easier to ride. since riding my 250 2stroke i have had more close calls on it than on my 450. the bike i like to ride more is the 250 though and thats because its fun, its exciting, and i love the smell and sound. oh and not alot of people like getting passed by 2 strokes. :)
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The easy-to-ride factor is what makes them dangerous, I guess. A two-stroke can do weird things and hurt you, but it lets you know in advance. If you get on some CR500 as a total beginner who's only ridden scooters, and step a little beyond your skill, it's going to do the bike equivalent of snapping a ruler on your desk and say, "Don't do that, foo!" With something like a 450F, though, it tends to be more friendly and open to going balls-to-the-wall fast. It's not really a big issue for riders of intermediate and advanced skill, but when you get someone who really doesn't know what they're doing, the four-strokes seem to all be sold with an express ticket into the proverbial pit of serpents.
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The easy-to-ride factor is what makes them dangerous, I guess. A two-stroke can do weird things and hurt you, but it lets you know in advance. If you get on some CR500 as a total beginner who's only ridden scooters, and step a little beyond your skill, it's going to do the bike equivalent of snapping a ruler on your desk and say, "Don't do that, foo!" With something like a 450F, though, it tends to be more friendly and open to going balls-to-the-wall fast. It's not really a big issue for riders of intermediate and advanced skill, but when you get someone who really doesn't know what they're doing, the four-strokes seem to all be sold with an express ticket into the proverbial pit of serpents.
i agree. but like you said its going to do it once and then they are going to learn not to it again. but you can say that about a 2 stroke to. first time they hit the power band and looper out they are going to know not to just pin it. its just a learning curve.
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I ride a 4 stroke all the time, of course it has 1100 cc, and is more of a cruiser, yes its a little tuff over the whoops, but cruises easily at 75 mph.... :D
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Some of my best years were back in the day wearing that great fashion icon.
That statement is worthless without a pic of you in the day. :D
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Maybe some things are best left to the imagination. ;D
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I admit I'm a little surprised how many haven't actually owned a modern day fourstroke and still say a two stroke is superior-which of course,they are :D
Anyhoo,I've owned both-street and dirt both.As for dirt,the 2t's were 99RM125,00KTM125EXC,02KTM124SX,02YZ250.4t's-96XR250,05 Husaberg FE550.
The XR was low powered and heavy but was a veritable mountain goat in the skanky crap and a great choice for that type of riding.
The Berg had loads of easily controlled power and torque and was a fine bike in itself.It was about 30lbs heavier than the YZ.Sometimes you didn't feel it,sometimes you did.
On the practice track,I used to shift my SX 13 times per lap-the Berg-twice.The Berg worked well on the track but if you got in trouble it was harder to bring it back.My 2t's would sometimes give a little shake and keep going but the same situation would have the Berg going side to side like a big pendulum trying to spit you off.
Interestingly,when I was used to my 125's,I could ride anything else(in my usual spastic way) with little difficulty.When I got used to the Berg,I had a hard time doing anything on a 2t.They do make you lazy in a way but big 4t power is still lots of fun-unlike a 2504t.I've never owned those but have ridden a few friends CRF's and YZF's.
In the woods,the first race I put the Berg in is the first one I never finished.Tight stuff is harder to handle as the gyro effect of the engine tries to keep you going straight-good on straights but bad on corners.Where you could flow on a 2t the Berg you had to be be on/off on/off the throttle in the twisties and turn on the off throttle.It works but it's an adjustment.The big disadvantage of the fourstroke in the woods is the fact that they overheat far easier than a 2t.In that race,I went down in a pile of rocks.I was unhurt but the bar has jammed between two rocks and I was pinned under it(the next guy along pulled it off me-thanks Todd :))Luckily it wasn't the pipe side.After getting going again,I still had about 10 min of first gear crap before the course opened up-I never made it.The bike started puking coolant out so I called it a day.I alleviated it somewhat by trashing the t-stat and going to Maxima Coolanol/Cool aide and while much better for 99% of my riding-the issue was still there.I could have put a fan kit on it but was loathe to add extra weight.
For me,I like both and each has an advantage in certain situations but by and large I'll take a 2t overall and be happy almost all the time.
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Maybe some things are best left to the imagination. ;D
On second thought-I agree.Disregard my original comment ;D
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::)kx125rider,To me 4-chokes remind me of a crappy old 1981 mullet!You know a Kentucky waterfall!Yeah they should have quit making the 4-chokes way back when the "MULLET"went out of style...And yes I have ridden many,many 4-chokes including newer ones and older XR's & as much as I hate Honda's I will say that the old Honda XR's were pretty reliable albeit HEAVY bikes.If your KX-125 does'nt have enough power for you by all means get yourself a 250 2-stroke and then you will see why everyone on this site loves 2-strokes!A newer 250 2-stroke like a 2007 & up Suzuki RM-250,Yamadog YZ-250 or a KTM-250sx will have enough power or maybe too much power for ya!Those bikes have almost as much horsepower as a new 450 4-choke!A KTM 250sx is only down about 2HP compared to a new crf 450r! ;)
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Thanks maicoman009!, but I wasnâ??t looking for a new bike. I had never ridden a 250 4t and I was just wondering how many people have actually ridden or owned one. Its hard to call something superior until you have tried all of the competition. I still like my 125, on the 250f it was really hard to get used to the power delivery. I am so used to shifting right as the power starts to fall off so I kept shifting the 250f right after the peak torque (8k) I had to force myself to rev it out more (13k)- it just didnâ??t feel as willing to rev as the 125. Bottom line I just like to ride motorcycles off road. The 125 is the best power plant for me right now. If the only option was a 4 stroke I would pay the price to ride. I did enjoy the bottom end on the 4stroke for the really muddy sections of trail-(it felt like a 4x4 quad ripping through mud a times). Maybe after ten more years of r&d they will be as reliable as an xr and then I would be willing to own one. But like I said I am perfectly content with a 125.
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i've never owned one but have a fair amount of seat time on YZ400F's, KTM 520 & 525 SX's, and CRF450's all owned by my riding buddies. the first YZ400F's were so heavy but pretty darn reliable machines. by far the most fun 4T bike i rode was those big KTM thumpers. i found myself over jumping stuff on them. their speed is deceiving because the revs were so low it was hard to tell how fast you were going. i have a total of two hours on a 250F, one a Kaw the other a Honda. to me they feel like XR's with good suspension. very uninspiring to ride. i never bought into 4T mx bikes because even when i raced it was for fun, not trying to shave every tenth of a second off lap times. two strokes just speak to me the way a 4T never will. i guess when you grow up hearing their sounds and smelling the fumes it's hard for me to imagine why anyone would want anything else. it is interesting to me that when the 2T bike ruled there was always some guy who loved thumpers enough to try to make a mx bike out of an XR and now when you show up with a 2T bike at the track you have become that guy.
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that's the thing, big bore 4 strokes have and can hold their own in open class racing as demonstrated during the 500 gp's during the 90's so why let them race against 250 2 strokes?
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If they refuse to give it up all dirt bikes will eventually become diesels. IT IS THE NEXT LOGICAL STEP.
Bullshit. they wont be diesle's, you only have to think about it for a second to realize that. ;)
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If they refuse to give it up all dirt bikes will eventually become diesels. IT IS THE NEXT LOGICAL STEP.
Bullshit. they wont be diesle's, you only have to think about it for a second to realize that. ;)
http://www.dieselmotorcycles.com/vehicle-m1030-m2.php (http://www.dieselmotorcycles.com/vehicle-m1030-m2.php)
(http://www.dieselmotorcycles.com/assets/images/m2-hero.png)
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Take a trip to europe and you will probable find that diesel cars out number gas engines, I thought I saw one of their manufactures just won a major event with a diesel we are talking formula type racing. But diesels due come in two stroke to go along with that tasty bullshit sandwich your chewen on! Thanks riff
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Wait a minute. If Ford shifted his SX thirteen times in a lap... that means that he couldn't possibly be in the same gear at the end of a lap as he was in the beginning. He had to either go up a gear or down a gear. Either there's some inconsistency, or at the end of a ten-lap race he'd be in 12th gear or something!
I know, normal people aren't supposed to think of these things.
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No one ever said you were normal jetz :P
P.S Fords have always bean strange ;)
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Wait a minute. If Ford shifted his SX thirteen times in a lap... that means that he couldn't possibly be in the same gear at the end of a lap as he was in the beginning. He had to either go up a gear or down a gear. Either there's some inconsistency, or at the end of a ten-lap race he'd be in 12th gear or something!
I know, normal people aren't supposed to think of these things.
JETZcorp - WOW!! You figured that out? Yet you left out one simple thing.. if you start out in first at the start, when you come around for the second lap you don't shift back down to first.
To quote Mr. Know-it-all "You should have known." ;D ;D ;D
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What if you started in 2nd?
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Or if you had a 490, you probably even started in third!
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If you were able to start in a higher gear, you wouldn't have to shift thirteen times in a lap! ??? ???
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Take a trip to europe and you will probable find that diesel cars out number gas engines
Yeah, they do. Well at least they are just as popular as petrol cars. The new diesels do pack a punch. The main reason why people buy diesels here is because diesel fuel is slightly cheaper than petrol, and a regular diesel has much, much better fuel economy than petrol. Besides, they last longer, although are more expensive to buy, and parts are also not too cheap (old diesel- bad idea :( ). But seriously, the new diesel cars have really great performance, especially the torque in the low rev range is awesome. Correct me if I'm wrong but I think diesels won the Le Mans recently, competing directly with petrol cars...
I wonder, what the characteristics of a two stroke diesel would be. What would a two stroke diesel motorcycle be like to ride. When you think about it, diesels are more efficient and reliable then petrol engines. Two strokes also have their advantages. If you pair up these two designs maybe you get the best motorcycle engine ever made ?
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Wait a minute. If Ford shifted his SX thirteen times in a lap... that means that he couldn't possibly be in the same gear at the end of a lap as he was in the beginning. He had to either go up a gear or down a gear. Either there's some inconsistency, or at the end of a ten-lap race he'd be in 12th gear or something!
I know, normal people aren't supposed to think of these things.
JETZcorp - WOW!! You figured that out? Yet you left out one simple thing.. if you start out in first at the start, when you come around for the second lap you don't shift back down to first.
To quote Mr. Know-it-all "You should have known." ;D ;D ;D
Exactly so.Standing start for both as most tracks I know of don't allow a rolling start ???
I actually never thought about it until my CRF riding buddy asked me so I started,did one lap and counted-13.Of course,consecutive laps would be 12 as I used 2-5 for that track but started in first.The Berg I used 3-4 and started in third.The YZ I shift 4 times.Starting in 2nd and using 2-4 for the lap.
On the other hand Jetz, if train A leaves Boston with two engines and 30 cars traveling sse averaging 30kph and train B leaves Chicago with one engine and loaded with 20 cars of Maico parts headed for scrap iron recycler......
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No one ever said you were normal jetz :P
P.S Fords have always bean strange ;)
Can't argue with either point there. :D
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Take a trip to europe and you will probable find that diesel cars out number gas engines
Yeah, they do. Well at least they are just as popular as petrol cars. The new diesels do pack a punch. The main reason why people buy diesels here is because diesel fuel is slightly cheaper than petrol, and a regular diesel has much, much better fuel economy than petrol. Besides, they last longer, although are more expensive to buy, and parts are also not too cheap (old diesel- bad idea :( ). But seriously, the new diesel cars have really great performance, especially the torque in the low rev range is awesome. Correct me if I'm wrong but I think diesels won the Le Mans recently, competing directly with petrol cars...
I wonder, what the characteristics of a two stroke diesel would be. What would a two stroke diesel motorcycle be like to ride. When you think about it, diesels are more efficient and reliable then petrol engines. Two strokes also have their advantages. If you pair up these two designs maybe you get the best motorcycle engine ever made ?
just look at WTCC (WorldTouringCarChampionship) petrol and diesel cars race neck and neck, dont reall know if theres any advantage between petrol and diesel in that series but they trade wins at least
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Wait a minute. If Ford shifted his SX thirteen times in a lap... that means that he couldn't possibly be in the same gear at the end of a lap as he was in the beginning. He had to either go up a gear or down a gear. Either there's some inconsistency, or at the end of a ten-lap race he'd be in 12th gear or something
Actually he could be.
Assuming that he doesn't count N to 1:
1 - 2
2 - 3
3 - 4
4 - 5
5 - 4
6 - 3
7 - 4
8 - 3
9 - false neutral
10 - 2
11 - 3
12 - 2
13 - 1 <-- Woo hoo! back in first!
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and it depends on the condition of the track and how long it was..
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9 - false neutral
Actually,the old SX was famous/infamous for this on a 2-1 down shift especially under power mid corner/berm which led me to low side face plants on numerous occasions.So much so that I stopped doing it and just left it in 2nd and burned the clutch instead-much to the dismay of my previously knee slapping,hacking and gagging riding buddies. >:( :)
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The diesels are competing in Le Mans, but they've got a handicap. While the gas cars have to be naturally-aspirated, the diesels can get a nice, fat turbo and some extra displacement to support their high-compression, low-rev way of doing things. When they allowed gas engines to be boosted and as big as the current diesels, some of them were cranking out upward of a thousand horses, which was so crazy it just had to be stopped.
The rules had to accommodate the need for a high capacity engine with a turbocharger and high boost, whereas both possibilities are no longer allowed for gasoline engines, as these had developed over 1,000 hp (746 kW; 1,014 PS) in several race series of the past.
One example is the Porsche 917 which, after competing in Le Mans, made a showing in Can-Am racing with a 5.4L engine (slightly smaller than Audi's new R10 Diesel Le Mans winner) with some turbos, producing over 1,500 horsepower in 1972. After that, the SCCA needed a way to get rid of these beasts (because no one could touch the German engineering) and so they declared that a car's mileage had to be at least - get this - three miles per gallon!
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At least three miles per gallon :D. Impressive numbers.
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With mileage like that, you don't even need a carburetor. Just run some hoses straight from the gas tank to the intake, and hook the throttle pedal up to 12 really big petcocks.
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Maico.
lol, sorry we've gotten off topic so i thought i'd mess with ya :P
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Mr KX125 Rider,
To answer your main question, Yes I have based my opinions on my own experience on both bikes. (Except for our freinds that have blown up their 250f's and weren't riding while they were saving up the $2500+ to fix it.) The two stroke is far, far superior when it has a fair comparison. You are comparing apples and oranges. Not only are you comparing a 125 to a 250, you are comparing vastly different years of bikes! There is no comparison between a 98 and lets say a 2005 and up. There are alot of variables involved when comparing motocross bikes. Rider ability, CC vs CC, Terrain (are they motocross bikes on a track which they were built for?), vintage vs vintage, chassis maintenance, chassis set up, engine maintenance, proper jetting, ect ect. I recommend that if you want to get away from that "slow, lazy turning", take that 98 kx125 to a turn track and practice, practice, practice. It will reward you with a heck of a good time and make you faster on what ever bike you decide to get.
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My buddy has recently acquired a 02 CR450F and I have now ridden it several times. It definitely is a different bike than the old xr600r as far as 4 strokes go. It's kind of like this: the old chevy truck had the same 350 v8 as the corvette but the corvette was highly tuned. Riding the 450 is like riding the corvette. Honestly tho, it's not as exciting as riding the yz250 and for the general playing we do the xr600r is vastly superior to the 450. I'm sure it's great on a track, but neither of us are really enjoying it for the play riding and we're not racers. Too bad too, cause it sure is a sexy bike.
If you could re-tune it like a 2 stroke, then maybe it would be a ton more enjoyable. A rev limiter comes to mind, knock it down to a safe range for one. We need to turn the idle up a little I think, as it dies often like a highly tuned MX bike should. Noise wise, at idle it's better than any bike we've ever had but rev it up and wow is it loud - like the yz490 with the blown silencer.
Now don't get me wrong, it's a neat bike. But for the play riding we do, I'm glad I didn't put my money into it.