General Discussion Forum

DO any of you now whethers its worth investing in trick pistons and rings, reed valves, head covers, conrods etc. or if its all just a waste of time!!!

 im a real 2 stoke fan and am very eager to show these 4 strokes up....

I know you can just rebore the head, but thats just making the engine large taking a 125 to like a 138......  but then where do u get the pistons and rings from

Please help

try wiseco piston kit is cheaper and far away better than stock. if you want a  big bore kit call RPM and get a 167CC kit.  

can u really feel a difference ? and so you think a big bore kit is worth it, and if u do get a big bore kit is it hard to get new pistons and rings ??

Just buy a 250 and be done with it.  If you're riding a 125 now and 125 four strokes are taking you down, then your engine is not the problem.  If it's the 250 fourstrokes that are giving you problems, then I wouldn't feel too bad about not being able to out-power a engine twice your size.

This whole bizarre concept of mixing displacements so they can compete is absurd.  It's like affirmative action for motorcycles or being politically correct in the new mass brainwash.

Also, the after-market for dirtbike gizmos is huge.  Make sure before you lay your money down, that it will really make a difference.  There is a lot of useless, crap on the market now.  Just because they say their product is great, or someone else says their product is great, or "I bought one and it really works great", do not make it so. 

A fool loves company!

Most piston companies make oversized pistons incase you bore it out.  They do have limitations though, if you go too big like some of these kits (the YZ125 167cc kit for example) they probably don't make a piston that size and you would have to buy it from the company that made the kit.  Will you see a noticable power increase from a big bore kit?  Yeah.  But if your trying to race then your bike won't be legal anymore.  As far as just replacing the difference, I haven't really noticed any big performance difference in any piston I've tried, just in how long they last.  Reeds are a good way to go if your looking for a little more mid-top end on your bike, but do your homework first to see which would work best in your bike.  If you have a CR or KX, I would go with a Vforce.  If you have a RM or YZ, I would go with a Boysen.  Have you put a pipe on your bike yet?

Do you think that there should be separate classes for two strokes and four strokes in order to make racing fair or what?  

yep i'd go with reeds.. it should put alot of life back into your bike if its not brand new.  I've got an 97' yz125 and i'm just as fast on a track as a 2005 yz250f. i can hang right with them. but going for a spin down some back road with a long open strectch in front of ya look out you'll get blown outa the water every time. . it's that extra gear that gets ya

It all depends on what you are racing against. If you are racing against experienced riders on 250 four-strokes then those aftermarket parts will be a waste of money. I ride a RM 125 that basically has everything aftermarket. I run VForce reeds, wiseco pistons, FMF SST pipe and Powercore II silencer. With those basic upgrades you will gain more power and better throttle response---- I have no problems with the four-strokes at the local track. If you know how to ride a two stroke to its full potential then those mods will definitely be helpful. As far as the bigger bore, I don't think its worth the money. If you have your engine bored to a 139cc it will set you back about $950. If you go to a bigger bore like a 167cc it will set you back about $2000. Instead of blowing $2000 on a bigger bore I had my engine ported and head modified for better airflow and more horsepower. Along with that I had my suspension revalved and also got a new race ignition. It all depends on how much money you have and how much money you want to blow. I'll be riding my 125 long after the thumpers take over.

BRAAAAAAAP!!

This is all true, but i love my 125, i have a 03 kx 125, that has run brilliantly for the past 2 years (ive had it from new) but now that im begining to ride it like it really should be im feeling a bit held back...... but i rode a 250 2 storke (yz) which was beautifull but it could eat me alive..... thats why im thinking about things like my suspention ( most important) and maybe some mods........ moving to a 4 storke isnt an option.... im an apprentiship and ( on road shop) and i work on 4's all day, and i just cant see how you can trust them for off road thers way 2moro things that can go wrong.... do u think i should move up 2 a 250 2 storke (they scary me abit) but i miote get used to the power, but my 125 i was really through around !!!! decisions decisions  

im in England so the prices are different but products are still the same though.... A big bore kit is £300.....  i love racing 4's and betting so i really want oto be able to get a head up on them  

Whether you move up to a 250 is totally up to you. It all depends on the skill level you are and how comfortable you are on a 250. Where do you ride at mostly? On the track or on trails? And also what is your height an weight?  

My thoughts would be to save up money and keep your 125 stock. Get to be a good rider, really good with the clutch, get faster in the corners, and get more confidence in jumping. Then, sell your 125, or if you have enough money just but a 250 2 stroke. They are awsome, and box stock they can keep up with the 450's.
My .02
Brandon  

2009 YZ250F Long Haul

Kawa250

"Do you think that there should be separate classes for two strokes and four strokes in order to make racing fair or what?"

I think there should be a 125 class, a 250 class, and a open class.  The 125's run in the 125 class, the 250's run in the 250 class, and all the others run in the open class.  If a 250 four stroke can't cut it against a 250 two stroke, then they got themselves the wrong bike.

Having 125, 2 strokes running in the 125 class with a, oh it's okay, 250 four strokes is just, dumb, dumb, dumb, and then stupid.

There is a big push to make four strokes better than they really are and I am not really sure why.  Environmental, better after-market, I don't know.  But this whole bit of mixing the classes is just silly.

Lastly, it may sound as though I don't like four strokes.  The fact is, I do.  I rode a Honda XR 500 for years and just loved it.  I have rode the newer 4 strokes as well and they are very nice.  But the 2 stroke vs 4 stroke thing is not my point.  It is the mixing and screwing up the racing classes that has wondering who is in charge.

Go for the 250 2 stroke! You will grow into it fast enough! Sorry to hear you are in England! Things there seem to cost a lot more than in the States!  

lol thanks your right and never forget the 7 months of winter have to go through!!!!! but i guess the states also has its share of #### weather.....

ya i guess wasting money on trick bits for a 125 is a waste, im probably gona spend more time on my 125 get really good and move up to a 250 in the new year sometime........ i just like the light weight feel of a 125 they so easy to through around and control......

This is the way i see the 2 and 4 stroke problem.... a 2 and 4 stroke produces teh same amount of horse power (125 - 250, 250 - 450
) but it all comes down to the power deliveery, and the way the 4's use the power...... which in theory gives u more tracktion (sorry bout my spelling) its all power delivery...... nd useable power. and yes they should be raced in different classes for sure!!!!!!!! also a 4's touque is just crazy, this is all wat makes them easier to ride, u have to be a special person to be able to race a 2!! keeping it in that sweet spot. its amamzing !!!