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Two stroke vs four stroke issue I've been having

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Been riding for about 27 years, primarily 2 strokes. Right now I own a 1996 Yamaha WR250Z two stroke and a 2012 WR450F four stroke. Given the oversized tank and tons of farkles on the 2T, they're within a few pounds of each other.

My speed, especially in tight single track is significantly faster on my two stroke, despite it not "feeling" as nimble as my four. The two stroke has worse suspension, is wider, etc. I don't understand why I have such a hard time zipping through single on my four banger like I do on my two. One thing I noticed, is that on a two stroke, I very heavily rely on clutch control to go where I want, and on my four stroke, it's the exact opposite. I use my clutch significantly less and rely significantly more on throttle control. I don't know if this makes any difference at all, but it very well may. 

Another thing I've considered is the torque curve. Though I have decent tractable torque before my PV opens (somewhat similar to a 300, but not quite as good), the vast majority of my power is made above 5000 RPM on my two stroke, whereas, I can blip the throttle off idle, and rip my arms off on my 450F, even with the ECU fuel mapping advanced and the ignition being retarded across the board. 

 

So what gives? Is it the torque right off throttle? Is it the lack of clutching that I do on the four stroke? Is it something else? I'm hoping this doesn't start a 2vs4 argument as that is not my intent; I just want to be able to keep up with my friends again on their Beta 300's. I can on the 2T, but not on the 4T. I'm just a sloppy mess on that thing most of the time. I just want to fix it.

 

I should potentially note that on my WR250R, for the 3 years I had it, I was able to keep up with them also most of the time, despite having a 275lb poorly suspended "always at the rev limiter" bike. 

Edited by malignity

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 The clutch is what keeps the 4T from ripping your arms out off idle so I would think you might to need to use it more on the 4T. I don't know how long you've had the 450, you may just need to commit to it and figure out how to ride it, they take different timing and technique. If you're riding tight woods with rapid right, left, right, turns, and trying to go fast, the 2T will probably always have an advantage though.

 The suspension on the 450 can be easily fixed, probably just a setup issue.

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Maybe you just feel more comfortable on the old 2 stroke? When you increase speed on your 450 do you start to notice handling issues? I.e doesn't turn as well, doesn't slow down as good? 

Inertia from the moving parts of a 450 causing handling issues is a real thing. 

But, could just be a seat time vs comfort thing. 

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You also mentioned a WR250R (25ish horsepower, heavy, poorly suspended, dual sport, 4-stroke).  So you are saying you are faster in a WR250R 4-stroke versus a WR450F four stroke?  It sounds to me like it has nothing to do with 2-stroke vs 4-stroke and everything to do with the 450 just being too much of a handful in the single track.  

If that's the case, have you ever considered a 250 four-stroke or maybe even a 350 four-stroke?  But if we are talking about new bikes then you should also probably consider a modern 2 stroke woods bike like a 150/250/300 XCF-W.

 

Doc

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Well I kinda have had the same issue. I own a 01 YZ 426fn 4 stroke a 84 YZ 490 2 stroke & a 82 KX 420 Im not sure if any of them could be classified as better than the next. All I know is Im faster on the 2 strokes than on the 4 stroke. I think its because of the instant power band on the 2 strokes like in sharp cornering i can almost dead stop and instantly be back up to speed out of the turn. On the 426 fn it just seems like i am lingering mid turn much longer and the power and tourqe seems to be slower. Dont get me wrong all three bikes have break neck power and tourqe and will put you on your backside if you are not on your A game. Who knows? I say maybe i need to ride the 426 more practice does make us all better riders. 2 or 4 ? Does it really matter?  I think they both kickass and I love to ride!!!!

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I could never carry any speed on single track on the YZ450F I had. The carbed 450s carry weight up high and, to me, feel cumbersome trying to execute quick, tight turns. There are plenty of guys that can do it, not me. When I switched to a 250F, the game changed completely and I became faster on it than on my 300 two stroke. 

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Every time you roll off the throttle the 450 is slowing alot  compaired to the 2t. You can't just blip it and coast. 

 

 The wr450 is a pig on  tight single track. 

 

 Why not a newer 2 stroke? Light,good suspension and plenty power. 

 

 

 

 

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It doesn't feel like a pig to me, and it's honestly got some of the best suspension I've had in a bike. I love the power that it has, and the tractor torque when I really need to crawl, but I admit that I'm extremely intimidated by the bike and it's power, despite (on paper) my 250 2T having more horse. (Porting, gnarly, Lectron, etc)

I put on a modified muddy track ECU to tone it down some as well as went to 14/50 from the stock 13/50 and I'm still scared of it, however I admit that it's still pretty new to me. 

The bike was a steal, and I got it from the dealership with only 6 hours on it. I've ridden it only for about 10. 

In hind sight I would have probably been better off with a 250, but I'm stuck now with a monthly payment and a bike that I feel can kill me considerably easier than my 250 lol.

I chose the four banger and I'm the only one in the bunch because I have hundreds of miles of trails near me, and often hoof it 10 miles or so to a trail head via pavement. The two stroke would have me numb from the neck down after two miles.

I guess I'm not sure where to go from here. I love it in wide open two track and really technical sloppy "pick a line and crawl with commitment" tough enduro type stuff like multiple fallen tree crossings in mud such where I'm at a crawl, but get me on the bark buster to bark buster single track with whoops and turns and everything else and I just can't seem to put it together on this thing. 

I really don't want to sell it at a loss because it's too much bike. :(

 

 

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1 hour ago, malignity said:

It doesn't feel like a pig to me, and it's honestly got some of the best suspension I've had in a bike. I love the power that it has, and the tractor torque when I really need to crawl, but I admit that I'm extremely intimidated by the bike and it's power, despite (on paper) my 250 2T having more horse. (Porting, gnarly, Lectron, etc)

I put on a modified muddy track ECU to tone it down some as well as went to 14/50 from the stock 13/50 and I'm still scared of it, however I admit that it's still pretty new to me. 

The bike was a steal, and I got it from the dealership with only 6 hours on it. I've ridden it only for about 10. 

In hind sight I would have probably been better off with a 250, but I'm stuck now with a monthly payment and a bike that I feel can kill me considerably easier than my 250 lol.

I chose the four banger and I'm the only one in the bunch because I have hundreds of miles of trails near me, and often hoof it 10 miles or so to a trail head via pavement. The two stroke would have me numb from the neck down after two miles.

I guess I'm not sure where to go from here. I love it in wide open two track and really technical sloppy "pick a line and crawl with commitment" tough enduro type stuff like multiple fallen tree crossings in mud such where I'm at a crawl, but get me on the bark buster to bark buster single track with whoops and turns and everything else and I just can't seem to put it together on this thing. 

I really don't want to sell it at a loss because it's too much bike. :(

 

 

  From your description it sounds to me like you went the wrong direction with your gearing, you might try 13/52.

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10 hours ago, motovita said:

  From your description it sounds to me like you went the wrong direction with your gearing, you might try 13/52.

Hm. Adding one tooth in the front is equivalent to reducing 2.72 teeth in the back in most bikes if I recall correctly. This would in theory make the gears longer, increasing top speed at the cost of low end torque, no? When I jumped from 13/43 to 13/47 on my WR250R, I could finally loft the front wheel off the ground. 13/47 and 12/43 we're nearly identical in ratios and I felt no difference when I went between them. Just did so because I was having an issue with the chain slider wearing with the 12T.

 

 

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Fourstroke for racing, twostroke for play :thumbsup: that's my motto now. After 20 years of racing twostrokes.  They don't compare at A level mx anymore.  But for trail riding, goon riding even woods racing. twostroke way to go

Edited by Motox367

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1 hour ago, malignity said:

Hm. Adding one tooth in the front is equivalent to reducing 2.72 teeth in the back in most bikes if I recall correctly. This would in theory make the gears longer, increasing top speed at the cost of low end torque, no? When I jumped from 13/43 to 13/47 on my WR250R, I could finally loft the front wheel off the ground. 13/47 and 12/43 we're nearly identical in ratios and I felt no difference when I went between them. Just did so because I was having an issue with the chain slider wearing with the 12T.

 

 When you installed the 14T front you increased your top speed and raised your first gear ratio, not sure if that's what you're saying. The taller gearing (14X50) will make your bike faster and jumpier in first gear.

 

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On 7/7/2017 at 0:07 PM, malignity said:

Been riding for about 27 years, primarily 2 strokes. Right now I own a 1996 Yamaha WR250Z two stroke and a 2012 WR450F four stroke. Given the oversized tank and tons of farkles on the 2T, they're within a few pounds of each other.

My speed, especially in tight single track is significantly faster on my two stroke, despite it not "feeling" as nimble as my four. The two stroke has worse suspension, is wider, etc. I don't understand why I have such a hard time zipping through single on my four banger like I do on my two. One thing I noticed, is that on a two stroke, I very heavily rely on clutch control to go where I want, and on my four stroke, it's the exact opposite. I use my clutch significantly less and rely significantly more on throttle control. I don't know if this makes any difference at all, but it very well may. 

Another thing I've considered is the torque curve. Though I have decent tractable torque before my PV opens (somewhat similar to a 300, but not quite as good), the vast majority of my power is made above 5000 RPM on my two stroke, whereas, I can blip the throttle off idle, and rip my arms off on my 450F, even with the ECU fuel mapping advanced and the ignition being retarded across the board. 

 

So what gives? Is it the torque right off throttle? Is it the lack of clutching that I do on the four stroke? Is it something else? I'm hoping this doesn't start a 2vs4 argument as that is not my intent; I just want to be able to keep up with my friends again on their Beta 300's. I can on the 2T, but not on the 4T. I'm just a sloppy mess on that thing most of the time. I just want to fix it.

 

I should potentially note that on my WR250R, for the 3 years I had it, I was able to keep up with them also most of the time, despite having a 275lb poorly suspended "always at the rev limiter" bike. 

Going from 2t to 4t bikes, it took me a while to get used to how much more I had to stay on the throttle on the 4ts. I think 4ts are a faster ride when PROPERLY ridden because of that fact... if you're not on the throttle you're slowing down significantly due to engine braking. This causes you to either be on the gas or on the brakes, no coasting. If you're not riding a 4t that way, you're gonna be slow. You have to ride the two bikes differently. Its difficult to ride a 450 in the woods because when you're on the throttle you get to "oh shit warp speed" very quickly if your throttle control (or focus) is even slightly off. I think you were probably faster on the 250 4t because there isn't much power to manage or enough power to make a little poo come out. Theres an old saying "its always more fun to ride a slow bike as fast as it will go than to ride a fast bike slow". Personally, I think you have too much bike for what you ride. If I didn't have big open stretches of power lines connecting my single and double track loops i'd be on a fe250 instead of the 350. I had to dial in my throttle and clutch control for single track because of the power and how the 350 needs to be ridden. I rarely use more than half throttle in single track on that bike (as long as I can carry my speed) and I usually ride up a gear in single track too. Double track sees some WOT and power lines are usually big WOT pulls.

Weight of that 450 is also an issue in tight woods unless you like a work out and are supremely confident on it. I got way faster going from a drz400 to a husky fe350. Yes the husky makes more power but power is not the primary reason I got alot faster. It weighs MUCH less than the dizzer and carries its weight MUCH better than the dizzer. It feeling so light and being able to toss it around gave me alot more confidence in the tight stuff. 

I think you either need to ditch the 450 or you need to log some serious seat time on it, figure out how to ride it (use the clutch man!!) and then get confident on it. If you can't make it your bitch and toss it around, you'll likely never be fast on it and it'll be a frustrating struggle. If that ends up being the case, sell it or trade it for a newer lighter smaller 4t or stick with 2ts. Thats my opinion on it. 

EDIT - why do you have the 450 anyways? Why not just ride the 2t all the time?

Edited by SenorThumpy

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Interesting. I was under the impression that with increasing my front tooth CS, I'd have wider gears, less torque, but higher speed. 

I went to the 450 4T because of the better road capability. Both my bikes are plated and street legal, and I found another 100+ mile trail system about 10 miles away from my house. After two miles of pavement on my two stroke my whole body has fallen asleep from the neck down. LMAO

I've taken my WR450F to and from work a few times, paved road there, trails home. 37 miles of pavement there, 66 miles of trails home. 

With all the aftermarket parts and farkles on my 2T, my 4T probably only weighs about 10-15lbs heavier, but I admit, it's definitely a handful at times. I'm not sure if it's because it feels heavier or if it's the engine braking or what. 

 

Do you guys think a G2 throttle tamer would help? I've put on the muddy conditions mapping on the ECU and that's helped a lot too, but could use a bit more. 

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You just need to get used to the WR450. I rode mine as a do-all bike for a long time.  It is a bit of a handful in single track and prone to overheating if it's really slow, but it should be better than the 250z in every respect.  

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22 hours ago, malignity said:

Interesting. I was under the impression that with increasing my front tooth CS, I'd have wider gears, less torque, but higher speed. 

I went to the 450 4T because of the better road capability. Both my bikes are plated and street legal, and I found another 100+ mile trail system about 10 miles away from my house. After two miles of pavement on my two stroke my whole body has fallen asleep from the neck down. LMAO

I've taken my WR450F to and from work a few times, paved road there, trails home. 37 miles of pavement there, 66 miles of trails home. 

With all the aftermarket parts and farkles on my 2T, my 4T probably only weighs about 10-15lbs heavier, but I admit, it's definitely a handful at times. I'm not sure if it's because it feels heavier or if it's the engine braking or what. 

 

Do you guys think a G2 throttle tamer would help? I've put on the muddy conditions mapping on the ECU and that's helped a lot too, but could use a bit more. 

oh ok, yea if you're on the street too then it makes sense. I get it. I think a throttle tamer would help a little but I think really figuring out how to ride the bike in the tight stuff is going to help you the most. Some focused riding on what you can do differently in different situations to be faster on the 4t vs the 2t and then following up with pure seat time is whats going to get you faster. The rotating mass/inertia of the 450s motor is def noticeable over a 2t 250 and could be playing into this. I'd bet the engine braking is playing a big role. I think the biggest thing is... you're a little scared of the bike. Its not something anyone really wants to admit but I think its probably the case. Seat time is the cure. 

You are correct about increasing the front tooth count, going up in the front one tooth is about the equivalent of going down three teeth in the rear. Its not going to make your gearing wider, thats dictated by your trans gear ratios. It will make a given gear taller tho. I think you understand that and wide gearing vs taller gearing is just semantics here. I'd grab a throttle tamer and then find a short section of trail that you're noticeably slow on with the 450 and ride it back and forth repeatedly until you can own it and really throw the bike around. I wouldn't even ride the 2t until you have some success with the 450. I'll bet that you'll end up being faster on the 2t once you can make the 450 your bitch. 

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I admit fully that the bike can be super intimidating. I've never had a bike that can wheelie at 75mph in 5th gear. No bike I've ever owned has been capable of this, yet I've done it a handful of times already on this beast. Though I've ridden pretty much my whole life, I'm a "fat guy" and typically "fat guys" and wheelies don't go together. I've never been able to learn to ride the wheelie, and quite frankly when I start doing one, I often times panic. Throw tight single track in the mix and it's super easy to lose your momentum. The only time I'll purposely do wheelies is on whoop sections of trail just to keep my front end from going into the valleys and stay on the peaks; and I'm not even sure if that's really considered doing a wheelie or just keeping the front end level. 

With all the trails I have by my house, unfortunately NONE of it is single track for me to even practice on; at least that I've found yet. It's almost all second or third gear two track, or truck trails that are extremely muddy and/or technical requiring lots of thought as to picking the best line without getting swallowed by the mud hole on either side, etc. Reminds me of some of the older school enduro stuff. Lots of multiple log hops while getting through mud, etc. I seem do to relatively okay with that with this thing too, but with that kind of terrain, it's not about the speed, just the accuracy. 

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On 11/07/2017 at 4:15 AM, malignity said:

but with that kind of terrain, it's not about the speed, just the accuracy.

2 months later, how'd you go with your goal to feel more comfortable at pace in tight trails on the 450?

A different throttle cam, and EFI map sound like obvious gains. Also did you go for a lighter clutch pull and higher idle speed (less engine braking).

On 08/07/2017 at 2:46 AM, 505 YZ125 said:

Inertia from the moving parts of a 450 causing handling issues is a real thing.

Absolutely!   The camshafts, big piston, rod and crank all add up to one big gyro. Plus there is the large counter-balancer shaft to stop vibration, but that makes the big thumpers stubborn to change lean and line quickly. It's simply impossible for it to feel as agile as a 250F or any 2 stroke.

To make a 450 feel more agile something which can make a big difference is the triple clamp offset.  With lower offset you get more steering trail and this allows the rider to more easily lean the bike over on entry into a corner. Feels like you have less tip weight. If stock WR450F is 25mm then 22mm would feel very different. Only disadvantage is stability on fast bumpy sections.

Carrying minimal fuel weight always helps. As does having less weight up high anywhere on the bike.

Then there is over heating issue. Where you need a fan and e-start. 

IMO, any modern thumper in tight trails is at a fun disadvantage to a modern offroad 2 stroke in tight trails.

 

Edited by numroe

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I've hopped on an XR 650 that a very good rider was complaining about, and also a CRF 450X. Both rides were on tight singletrack and I usually ride a CRF 250X. I found both intuitively rideable, and credit this to my ingrained use of the clutch. I learned to ride on 125 2t bikes, so using the clutch is natural to me. The clutch is your friend. Hopefully you've got one or two fingers on it most of the time in singletrack (not four).

 

Regarding the heavy weight bikes, a great way to make any bike more flickable is to ride it standing. All your weight on the pegs, not the handlebars. Use the pegs like an airplane's ailerons by pressing more weight on the peg which is in the direction you want to turn. Right peg for right turn initiation. Lead this with your body leaning right as you nudge the left shroud with the inside of your left knee. All these actions in tandem will allow the bike to quickly bank into the turn. For traction/control, be sure to transition to weighting the outer peg once your turn is initiated. I was always taught to weight the outside peg, but doing that while standing really slows turn entry/initial lean. The opposite inside knee really helps "leverage" the bike over quickly. Practice in a safe, open area at low speeds.

 

Countersteer.

 

I hope that makes sense. Maybe you're already doing all that already. A bike is made up of gyros and pivot points. Once I understood this better, my control and safety vastly improved. Weight on the pegs, not on the bars and a loose grip really help the bike handle better.

 

 

 

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