Biggest motor that'll fit in yz250..?

[yz250yz]

Well I have a 2 stroke yz250 but i'm looking to put the biggest 4 stroke motor i can fit in it but have no clue what would be the best motor to fit in without a ton of fabrication.. If this is even doable that is.. I'm not very knowledgable on it all I just want help to look in the right direction so i can read up on it. I'm hopeing i can get a 450 in or something and make it street legal. (by the way the current motor siezed up when i was trying to sell it to someone, let them ride it a day at their place and didn't put enough/any oil in it and gave it back to me.) So it's needing a new motor anyway.
It's a 96yz..
Thanks.

 

[2strokerfun]

They should have given you a new engine when they gave the bike back.
Anything can be done, given enough skill and money. The question is why?? You'll be money ahead buying a street legal four stroke. There is no way to do what you want without a "ton of fabrication" and a ton of headaches. A ton of cash would also be helpful.
Just my 1.4 cents (taxes)

 

[IndyMX]

I agree..

In my opinion, if you work to put a 4 stroke in that bike, then do what ever is needed to make it street legal, you are going to spend way more money and time than if you just buy one that is already street legal.

And you'll end up with a hacked together bike, with an inferior frame & suspension.

And a big hole where your money used to be.

For a couple thousand you can have a good quality street legal dual sport, and spend a few more dollars to fix the 250 motor and you'll have a good working MX bike.

 

[yz250yz]

Thanks for the input guys. I rebuilt the top end but apparently the bottom end got screwed too.. I figured it would cost a bit more to rebuilt the bottom end than just a couple hundred guess i need to do my research! haha thanks again.

 

[helio lucas]

honestly, it will be very hard to fit a four stroke engine in a frame build for a smaller engine(unless you are service honda). but beside that, why do you want a high performance 4st instead of a high performance 2st? :whoa:

not saying that one is better than other, but since you have to put a lot of work and money, why not a xl650 air cooled engine, or other like this??? less maintenance, same power (more or less), same noise, and improved reliability, ok maybe more weight and more difficult to fit, but nice...
or a cr500 engine... :blah:

 

[Matt90GT]

1500cc Hyabusa motor will fit! Just take some work.

 

[spark250]

small block chevy!!

 

[2strokesrock]

small block chevy!!

LOL..I think if would be fun to put a V8 in a ATV...

 

[areaman]

small block chevy!!

thet wuld be dum cuz u wuld not be eble to jump it if u did that i think u shuld prolly get like a xr200 motor and put in their it wuld hav good sspsnsion and whatnot and be a good tralebike wich wuld be kind of awsome to have with good spsensnion and a chpeap motor that wuld last a long time.

 

[Deadohiosky39]

^ By the quality of the spelling in your post I can tell that you didn't understand his sarcasm. Good luck next time.

 

[Rich Rohrich]

^ By the quality of the spelling in your post I can tell that you didn't understand his sarcasm. Good luck next time.

Yeah, he's the one that doesn't recognize the sarcasm. :rotfl:

 

[dirt bike dave]

Just rebuild the YZ250 motor with a big piston, and get it ported for the power delivery you desire.

If you don't like the result, sell the bike and get a 4 stroke.

 

[Deadohiosky39]

Yeah, he's the one that doesn't recognize the sarcasm. :rotfl:

Damn, i just went back to read his post. Can't believe i didn't get it the first time. It was all spelled so bad i didn't really pay too much attention to what he was saying. Boy do i feel dumb :bang:

 

[areaman]

i dont undrestnd what ursaying dedohski39 im sireous about this it wuld be a good bike if u jus put a descent motor in a good hitek chassy like that it wuld go anyware and be prety aswemom

 

[2strokerfun]

And we all love aswemom bikes! On a good day, mine is the aswemommiest.

 

[Ol'89r]

Allison V12. That would be more awesomner than a small block chebby. IMO. ;)

 

[holeshot]

i dont undrestnd what ursaying dedohski39 im sireous about this it wuld be a good bike if u jus put a descent motor in a good hitek chassy like that it wuld go anyware and be prety aswemom

What the heck ... maybe this guy isn't being sarcastic ... :rotfl: