Quick Poll. 2-Stroke, 4-stroke or both

[2strokesrule]

2 stroke of course I will probably never purchase a 4 stroke.

 

[robwbright]

2 Stroke.

I posted this somewhere here before, but my father-in-law just finished 4th at Daytona in the World Karting Association / ICC 125 Sprint 1 class. He's a 30 year+ wuto trans mechanic, 40+ years auto racing in everything from sprint to modified dirt to karts.

He would not touch a 4 stroke at this time for any reason - he's using a Boyesen built 98 CR125.

4 strokes are beginning to hit the karting circuit - same displacement advantage.

They're either broke down or in the back of the pack - usually broke down.

I'm not sure what that means, but it seems to him and me that the 4s are not capable of running at 13,500 rpm non-stop for 15-20 minutes. The 2s are certainly proving more reliable there and better results.

You can't win if you don't finish. :aj:

 

[Avena Quaker]

2-Stroke for me, I don't race so don't care for any possible advantage a 4 stroke could give me, my bike is just plain fun and that closes the deal for me.

BTW I didn't expect this results either..

 

[joshp]

4 strokes are for people that can't take the snap of a two stroke or for people that idolize the pros and want to be like them in everyway.

 

[joshp]

It sounds like you have experience with older four strokes, like the XR. On these bikes, the valves are steel like you said, no coating, generally checking and adjusting the valves is something to do on a rainy sunday afternoon...they just don't move much or require much maintenance. The new generation of four strokes are a different story, I think the titanium nitride layer on Honda valves for example is about .0002" thick (i've analyzed similar parts with similar processing but haven't cut a Honda valve yet). It's very hard on the surface, way harder than the seat but very thin. Once you wear through that it's time for new valves.

regarding oil usage, if a two stroke is jetted properly most of that oil gets efficiently burnt, and doesn't even make much smoke. Yes, there are some emissions you can't see. The four strokes have issues too, just different ones. Have you heard about the CRF250 Hondas that people are running out of oil when new? Some of them actually use quite a bit of oil, especially when not broken in yet. Where does that go? Also, the oil changing maint schedule on new four strokes has you needing to dispose of way more oil than a two stroke. Where does that go? Some of it is disposed of properly, some of it no doubt is dumped in the back yard or the storm sewer.

I think the starting issues have more to do with the four only coming up on the compression stroke once per kick, plus they seem to be more picky on having just the right fuel/air mixture. I'm really not sure of all the reasons, just know which is easier to start, especially when dropped.

at the end of the day, the bottom line is that if the factories spent all of their resorces just on the one engine design (two stroke), we would have a lighter, more powerful, simpler, cheaper bike. But, no use in fantasizing about it, that's not our reality.

I personally believe this is all strictly a government push to two stroke; eventually they'll all be four strokes like the street bikes. I believe that is also why 450's are allowed to compete with 250's on the track. I think the government may have had a hand in it indirectly.

 

[OZKX250]

4 strokes are for people that can't take the snap of a two stroke or for people that idolize the pros and want to be like them in everyway.

Probably coming from a person never to own a 4T.

I have owned both and prefer 2T but to each his own.....

 

[robwbright]

I personally believe this is all strictly a government push to two stroke; eventually they'll all be four strokes like the street bikes. I believe that is also why 450's are allowed to compete with 250's on the track. I think the government may have had a hand in it indirectly.

They can make a 2 stroke pretty emissions friendly (not that I believe they're really much of a problem in the first place), but they're not doing it.

Thus, there are only really three possible factors:

1: Government regulations and pressure;

2: More money in selling 4 strokes;

3: People like 4 strokes better.

Obviously, the potential for making money on 4 stroke rebuilds is MUCH higher than with 2 strokes, so there's part of the answer.

Looking at the poll results, at least around here, factor 3 above is not the reason they're focusing on 4 strokes. If there were no displacement advantage for the 4, the % of people who prefer 2 strokes would be about 90% or so, I'd guess.

 

[wardy]

I posted on another board that its' possible that an amatuer rule change could happen to make the cc's the same no more handi-caping..... the next post was thats not fair,

4 stroke can't compete with 2 stroke heads up 250cc.
well duh. guess there it is, change the rules now that the "thumper" has been developed back to what they should be and lets go racing.

they were called "cheater" bikes back in 98,99, now the difference is that everyone is on one that races MX/SX.

wonder how well that will be recieved.

:think:

 

[robwbright]

How's this keep getting moved to the top?

 

[Okiewan]

How's this keep getting moved to the top?

By posting in it? :laugh:

 

[robwbright]

By posting in it? :laugh:

No Wardy's post just above was posted on the 9th, yet this was still on the last day's posts this morning when I asked the question. It hadn't been posted on in over a week and yet remains current . . . ??

 

[Okiewan]

Ah..
Mods have the ability to bimp threads that without posting in it... must be it.

I would imagine it was bumped because it's relative to the project bike (going 2 or 4).

 

[Jaybird]

It's a poll. When anyone responds and votes in the poll, the thread gets bumped to the top as if there were a new reply.

They guy who hacked this place out could probably fill you in some more...

:)

 

[wardy]

I don't BUMP nuthin, unless it's gomer in the first corner at Cooperland,,,, and he likes that sort of thing!!!!

but i wondered what was up with that myself, I keep seeing "new" posts but I didn't add anything, this 2 vrs 4 deal is going to be a long on going thing........ I beat that horse enough for a while :)

 

[2fittyjeff]

I have an older 250 2-stroke and a new 250 4-stroke and think the sales pitch about the 4-stroke having a much wider power band is true, But I should have done more research into the increased maintenance and repair costs, I really think the twin cam 4-stroke design isn't compatable with high revs, at least not enough for long term use. too many moving parts. I'd rather ride than wrench.

 

[robwbright]

I'd rather ride than wrench.

Amen to that . . .!

 

[JBlinky67]

But what about offroad? This is all fine and dandy for mx, but do the same opinions apply for enduros? I personally feel that a big 450 from check to check with a special test is totally worthless. (except maybe with a rekluse) A 2-zinger 250 is the bike of choice. Lightweight, zippy power that restarts easily (another reason the rekluse is so awesome), and low maintenance! Plus, for as much track riding I do, which is no more than playing around on the jumps on my local off-road park mx track, it's pretty much the perfect bike.

 

[Avena Quaker]

After riding 4 strokes for a few years, I went back to a 2 stroke. I'm not going back to a 4 stroke until I can't ride a 2 stroke anymore.

Bike(s): '05 KTM 950, KTM 450, YZ 250F :think:

 

[jt1872001]

ive ridden a crf450 yz450f wr450f out of the 3 i like the yz450f best but when i got back on my cr250 i knew it ruled those bikes ... but in drag races at the dunes i get beat but just barely by 450's.
sadly i will be selling my bike soon ..but only to get a 2006 CR250R bring bring bring braaaaap!

 

[funfactor1]

The 2006 YZ250 2-stroke is an awsome track bike as well as a woods bike completely stock. If you are out just havin fun you can't buy A better bike period.Long live the 2-Strokes : :cool:

 

[YamaB]

I have both... I started with a 2-stroke, but gave it up for the torque/ridability of the 4-stroke... I love the 4-stroke, but missed the excitement of the 2-stroke... Thus, I kept my 4-stroke and just bought a 2-stroke to play around on...

 

[Masterphil]

I started on a 4T, now I've got a 2T and the only way I won't be riding a 2T is when they stop making them.

 

[tartersause12]

2-stoke is the way to go so much quicker

 

[FINGERLESS]

i have a 93 cr250 and a 01yzf426. ive been ridin the 4 stroke more but that is just because my crs suspention is shot.i think i would rather race my 2 stroke though its lighter and quicker to start after a stall

 

[Kew-rider]

I do remember a dyno-chart I looked at online where they were comparing a modern 4-stroke vs. a 2-stroke, I looked at the RPM, and the four was almost as much as the 2T! can it be that the reason that the four-stroke MX bikes are said to be faster only because they have twice the amount of cc's and rev almost as high? or was it that the person who made the chart was wrong. I had a TTR-125ES with the little tires and electric start, but then I got my CR, way way way faster. The extremely high RPM would also explain the short piston life of the 250 and 450F's.