The biggest argument in MX - Two stroke or Four stroke? And why?

[nashie]

These days, with fuel injection, 4 strokes have just about as much get up and go from low revs as a two stroke does. 4 stroke all the way for me.

[FujiwaraTofu]

Two stroke's are super fun, equally as four strokes. Thing that sucks about two strokes is obviously mixing the gas, and they go through top ends hellafast. However its not super expensive to rebuild. Four Strokes are a B*tch when it comes to maintenance though. Most 250 race bikes have to have the valve clearances adjusted all the time because they get revved out alot more. and when you blow a top end, its a grand at least. Maybe more. 450's are less prone to valve issues because they don't get revved off the limiter a lot... Hopefully. Two stroke is honestly probably better. But since I don't ride anything but Honda's, I'll be on four strokes. (cause they don't make two smokes anymore. )

[ArkaTek]

Two stroke's are super fun, equally as four strokes. Thing that sucks about two strokes is obviously mixing the gas, and they go through top ends hellafast. However its not super expensive to rebuild. Four Strokes are a B*tch when it comes to maintenance though. Most 250 race bikes have to have the valve clearances adjusted all the time because they get revved out alot more. and when you blow a top end, its a grand at least. Maybe more. 450's are less prone to valve issues because they don't get revved off the limiter a lot... Hopefully. Two stroke is honestly probably better. But since I don't ride anything but Honda's, I'll be on four strokes. (cause they don't make two smokes anymore. )

I've seen full rebuilds for a 250f Cost upwards of $3.5k, obviously that is like having a whole new engine but it is alot of money, even top end is a big spend. I ride an 07 yz250f, it only has 65 hours on it since new and the only thing I've had done to it is valve clearances and it's looking at a new chain and sprockets before my next ride. Luckily I have a friend who's an ex Yamaha mechanic who does all my work cheap, but the rest is just the air fiter after every ride and oil every 5-10 hours. I do really like the scream of a 2 stroke, but the fours have been developed alot more than the two's, simply because they are easier to ride. A two stroke is loads of fun, but take one on a 5 day trail ride and you'll want to go home by the end of the 2nd day with only a few exceptions (KTM 300's for example). Fuel injection has obviously been a big plus for the new four strokes, and it'll be interesting to see if Kawasaki can make the dual fuel injection work reliably.

If you're looking to race on a budget for a bit of a bash on the weekend, a two stroke will be cheaper in the long run and loads of fun, but for anything else it's pretty hard to look past the four strokes.

[Hyde]

I used to ride a KX125. Never had problems with it being too powerful or too much of a handful ever, quite the opposite in fact, which makes it so fun on trails. You really have to work on your riding to keep things flowing, rather than letting the torque of a larger motor pull you out of trouble. Great bike to learn on IMO.

[NetworkFart]

I do have some experience in this field, I have raced four strokes and maintained my own bike. You would benefit greatly from riding a four stroke, faster bike. and hellacheap to maintain if you can do it yourself. get an hour meter, change oil every 5 hours, gearbox oil every 7.5 hours and oil filter every 10 hours. and don't forget clean your air filter every race day. I have never done anything to my brothers bike in the 7 years he has owned it but change rings and keep up with servicing. if you keep up with maintenance you will never have a problem. and plus.. Four strokes are faster, last longer and sound so much better.

[s13mikesr20]

4 stroke can use turbo
2 stroke revs very high(but no turbo or sh%t will hit the fan)

my opinion
4 stroke just fill up and go
if it comes down to which one is easier to work on basicly both motors have to come out in order to rebuild 4 stroke just uses more parts which equals more time
2 stroke its messy leaks 2 stroke oil every were after the exhaust port have to pre mix(less ride time) eats more gas

id say ef it run a 1 rotor hahahaha jk

[Chaos_reaper]

2 strokes for messing around, racing, having fun. (more maintenance and cost)
4 strokes for trails, a to point b, driving on road, (less maintenance and cost).
If i had the choice, i would own both. i had a yZ125 2 stroke and a 4 stroke yamaha, honda.etc and i loved my yz

You've got that backwards

2 strokes have less moving parts therefore need less maintenance yes they may wear out quicker but unlike 4 strokes you have to adjust valves and tighten the cam chain every now and again.

Think about doing a top end rebuild
The cost for a 2 stroke top end is around $300 whereas the cost for a 4 stroke top end rebuild will be almost 4 times as much as the 2 stroke

[Krafty]

if you stay up on the maintenance on the 4 stroke you wont have to do piston and rings for at least a few years. 2 stroke is every couple months. and that's if you race. occasional use 4 strokes last decades on top ends. a two stroke used occasionally would be a couple years on a top end.

competition 2 stroke at 300 a top end (to get somebody else to do it) 3 a year that's $900 for one race season per bike.

$80-120 each time if you know how to do it. it takes me 2 hours to do a top end.

plus a 2 stroke race bike should get a carb clean every week to 2 weeks when on the circuit cause they are picky when it comes to air/fuel to get max power.
which negates the 4 strokes needing valve checks for maintenance,

4 strokes are easier/ cheaper to maintain, better emissions, and produce more power. that's why 2 strokes are dying

[Chaos_reaper]

Yamaha has said themselves that they're only still making the YZ two strokes because they're overall a cheaper bike to maintain

This is a direct quote from the Yamaha website for the YZ250 2 Stroke

"The 2-Stroke Lives!
The YZ250 is the standard by which every other 250cc 2-stroke motocross bike wishes they could live up to. With giggle including power, unbelievable lightweight handling and legendary Yamaha durability. Plus, 2-strokes are easier and cost less to maintain!"

Quoted from.

http://www.yamahamotorsports.com/sport/products/modelhome/30/home.aspx

[Mr. Two]

Because brappity brap?

[Hankey]

Anything less than 100CC, go 2 smoke.

Bigger than 100CC, go four stroke. It just seems simpler to upgrade to me.