It490

[atcpunk107]

Awhile ago my father bought a motor off the internet for his 84 XT250, he wanted a 2 stroke so he went with a 2 stroke for 250 bucks, that was about 3 years ago, we got it on the bike and ran it rill the rings went bad, when we took the head off we figured it was no 250, we took the piston out and it was an aftermarket wiseco so we ran the numbers and it came back to an IT490 bored .50mm, talk about wondering why it seemed like it had more power than a normal 250 two stroke, well we are now putting it back together and building an exhaust for it, does anyone in here have any experience on the motors, are they dependable or no. any info would help thanks, i want to know as much about the motor as i can.

[rob0781]

it490's came in the old enduro yamaha bikes,they are 2 stroke but they have no power band i almost bought a whole bike from a guy i know i guess there pretty reliable but aren't to powerfull,no comparison to a cr500 motor that for sure..

[OldSchoolin86]

No power band?

[rob0781]

nope just like 2 stroke street and trail bikes they haven't got a powerband..

[200xman]

I'm sure you can find a powerband for it on Ebay!!!! :rolleyes: :D :rolleyes: :D ;)

[atcpunk107]

ok now what is a power band

[corndawg]

ok now what is a power band
where the peak power is

[OldSchoolin86]

I'm sure you can find a powerband for it on Ebay!!!! :rolleyes: :D :rolleyes: :D ;)

LMFAO!!! :D :D

[PLJ.]

No power band!!!! Most of you have probably never even rode a big IT before apparently. Do any of you remember the YZ465 or the YZ490?? The later being one of the most abrupt two stroke motors ever built!! Explosive midrange power, some even called it uncontrolable. Look closely and you will see that the IT465 80-82 and the IT490 83-84 are basically YZ motors with slightly different exhausts, light coils and a few other minor changes. Do not think for a minute that these 50 plus HP dry dogs are slow, they may be hard to start, hard to stop and hard to turn but nothing stock in the dirt besides a newer 250 MX or another open bike can beat one-PERIOD. P.S. I sold a mint 82 IT465 last year and had to ship it to London, England. THanks.

[rob0781]

i drove a freshly rebuild one iut was bored out to a 505 amd it was a slug,i'd put money on a cr125 against one of those old slugs..

[TrikeKid]

No power band!!!! Most of you have probably never even rode a big IT before apparently. Do any of you remember the YZ465 or the YZ490?? The later being one of the most abrupt two stroke motors ever built!! Explosive midrange power, some even called it uncontrolable. Look closely and you will see that the IT465 80-82 and the IT490 83-84 are basically YZ motors with slightly different exhausts, light coils and a few other minor changes. Do not think for a minute that these 50 plus HP dry dogs are slow, they may be hard to start, hard to stop and hard to turn but nothing stock in the dirt besides a newer 250 MX or another open bike can beat one-PERIOD. P.S. I sold a mint 82 IT465 last year and had to ship it to London, England. THanks.
my thoughts exactly ive talked to people with IT490's and they said they were major screamers the larger flywheel in the enduro was all that made it controlable for most people. rob you would lose that bet. whens the last time that you heard of a cr125 roosting rocks for 40 feet. i mean geese my dads MX360 wouldnt have to work hard to beat a CR250 and that came from a guy who rides a CR and took the MX for a spin.

[atcpunk107]

so the motor in an XT250 frame should do pretty good

[coyote killer]

I've got an 85 YZ490 and I can assure you they are beasts.....only thing that can beat it in a drag race is the newer CR 500'S and KX500's.....Its one scary ride and I'm sure the slightly detuned IT490's are beasts too....

[simonswanson]

nope just like 2 stroke street and trail bikes they haven't got a powerband..


well they must be big bore 2 strokes for girls.
Also I had a 1989 kawasaki KR1-sp 250cc 2 stroke road racer and that cirtainly had power band and for it's time they were the fastest 250 out of the box . Brand new with a port and polish it would hit 285 km/ph

Now power band my A**E I think Rob was to scared to turn the throttle far enough to get into the power band


:twisted: