General Discussion Forum

Just got an older YZ250 2 stroke, and wondering what now?  Had a 4 cyc for way too long.  Anything specific to look for when combing over this rig?  thanks! 

hey, what exactly are you asking? i used to have a 1 cycle but now i have a 2 cycle(4 stroke) wel i guess you should go ride it, is it pipey,waht year is it, good job on getting a yamaha, well post more info soon. ok?

bubba, theres no such thing as a 1 cycle. there are only two types of motors in dirtbikes. 2 cycle (2stroke) and 4 cycle (4stroke). not knowing what year yamaha it is, i cant really tell you specific things on your model year. you said its older, but im guessing its post 1990. do you know what the previous owner ran gas wise? which type of oil and to which ratio it was mixed? two strokes arent that hard to maintain. its the reason i ride one. (being in high school i dont have much money to put into my bike if it breaks) as long as you keep up on simple maintenence, ie: change the tranny oil. you should be fine. every once in a while i'll take out my carburerator and make sure its clean. i also do this with my powervalve. powervalves tend to get gummed up with burned oil. if you dont know what a P.V. is, its a valve on your cylinder which opens up to the exhaust on your bike. its important to keep it clean and free of goop. if you were able to maintain a 4 stroke properly, you'll have no problem with a 2 stroke. the motor may not live as long on a 2 stroke, but its a do it yourself job, and is fairly inexpensive to replace the top end.  

actually techcically speaking, there is for every 2 strokes of the piston, the crankshaft rotates once, thats 2 strokes=1 cycle/revolution of the crank, that makes a 2 stroke a 1 cycle and  stroke a 2 cycle. but unfortunatly the masses have yet to grasp this concept and insist that a 2 stroke/2cycle is the same and a 4 stroke/ 4 cycle the same, this is techically incorrect but is seen as correct to the masses.

here are some sites to prove it:

/www.motocrossactionmag.com/ME2/dirmod.asp?sid=&nm=&type=news&mod=News&mid=9A02E3B96F2A415ABC72CB5F516
B4C10&tier=3&nid=53114BA8F1CA41BF9EA80AF228D98ED0

now on the first one go to the bottom and very last paragraph, all the guys that work here are super smart.

http://auto.howstuffworks.com/engine.htm

now if you look closely you can clearly see that every 2 strokes of the piston consists of one recolution of the crank. in 4 stroke engines it 4 strokes of the piston to complete a power cycle. and 2 revolutions/cycles of the crank. therefore a 4 stroke is a 2 cycle. ask almost any one and they will deny it at the drop of a hat because it has become accepted incorrectly in the american language. language is by definition the speech of a country, group, or region and 4 strokes are beleived widely in the U.S. and all over the world that they are also 4 cycles. i hope you can understand and see my point, sorry i wrote so
much

sorry - 1995 yz250  Noleen pipe/silencer - boyesen covers, billet clutch basket and kicker, new top, fork seals, brakes, plastic, seat cover, protaper bars, so far needs both sprockets, chain, and grips.

not sure on anyting else - he was not there his dad was selling it for him, the kid was away at school - got it for a song *$500* so took it (with the original title) and ran!!

Welcome to the YZ250 club! Being as its a older bike, I would want to know when the last time it had a top end. Also what he ran for mix, I would run 32:1 in it, Check Every thing! Grease, Lube, Air filter, plugs, chain, NEW OIL!!!!!!!! Tires, spokes for true, Cooling fluid, Tighten all bolts to spec. And you REALLY want to know when it had a new top End.  Keep up on the maintence and that bike will give you lots of fun! If you dont know how to do alot your self, Spend a few dollers and have it looked over by a yamaha dealer. Its not that much! Good luck and have fun! Also.. If you have the manual, READ IT!! If not GET ONE!

Just look for the occasional detonation pinging and mixing gas. 2-strokes are way more simple than 4-strokes. It also takes way more less transmission fluid so don't freak out if you put less than a quart in. Other than that Long Live 2-strokes and Braaaap!  

Long live 2 strokes, hey....... Too bad they will be gone in less than half a decade. Four strokes have too many advances in technology and deliver a far more smooth and broad powerband at a more controllable level. Two strokes are stinky, noise and air-polluting pigs that need a pro to ride to their potential. I'm sure when you were all kids you rode 2 stroke trail bikes, right? Now look at the trail-bike market; it barely has any 2 strokes, the majority of them are 4 stroke. Even motocross bikes are being taken over by the 4 strokes. They are making 250 and 450 four strokes because they are so much better. Try taking a 2 stroke for a long 6 hour ride; you'll be out of fuel between 3 and a half or 4 hours. I personally wouldn't have bought an old 2 stroke, it probably has more problems than someone in a mental hospital, needs more work on it than any 4 stroke would ever need, and will last you no more than a couple years.    

Im not going to get sucked into a 2 stroke 4 stroke argument. I just want to say that your wrong! The best woods riders in the world ride 250 2 strokes! Apparently you dont follow the GNCC, The best woods riders in the world! Shure you don't want to go back and do alittle home work before you post back????  PS. Welcome to the board! Where all comments Are welcome.  YZ WOODS.

Ummm, Yeah.  why not start a ford/ chevy debate, too, as long as you are hijacking the thread, dork?  Other than that, for what I have in it if I only get a few more years it is well worth it.  Had it our yesterday all day without a single hitch...ran fine for me both on track and in woods.  thanks for all the helpful suggestions,

Don't sweat Donato8; likely had a bad experience.  I agree it takes more skill to ride a 2-stroke but thats what makes it so fun and a thrill.

2-strokes will be around for awhile.  4-strokes are OK but having had both I will stick to the 2-stroke for my fun.  If racing; well in MX etc you pretty much have to run a 4-stroke due to the extra cc displacement they give them.

But for fun, I also like the 2-stroke.

I would add one thing to the suggestions so far:  check/change the suspension fluid.  If its been in there for more than a year its probably burnt to *** and changing it will show you a world of improvement and allow you to tune the suspension accurately to your needs.  Also, set the sag for your weight.  Try to find out if the suspension is stock.  If the previous owner had it modified for his weight and riding conditions you might not suit it without some set-up time.  Definitely check the linkage bearings!  I bought my previous bike from a dealer and didn't check the bearings (dumb dumb dumb).  After two fairly short rides they were toasted because they hadn't greased them after the dealer got them all full of water.  I had to wait over two weeks for them to get parts and labour done (though kudos to them they did fix it for free).

Also a note on the necessity of racing a 4-stroke.  I run a YZ250 (in the MX1 Novice in BC) and just clinched the series with one round left.  There are quite a few guys out here that are still on two-strokes - even in the 125 class where the disparity is largest.  And they aren't just the guys out for a few laps, a lot of them are front runners and I have seen quite a few motos won by the 2-smokes.  Unless you're running pro (and even a couple of them are resisting) you don't NEED a four-stroke to be competitive.