03 yzf 250 hot rod help

hey guys need a little advise:banghead:

built an 03 yz250f .

it has the following mods high compression piston,major porting,huge cams,sick fast intake inserts(before and after carb)

the bike is a toy my son and i are riding around the yard we've been riding it with stock pipe

that was not right so we got the fmf powerbomb header,mid pipe,and the factory 4.1

how big of a carb can i get for this monster

Stock carb is plenty big. If you want to make it faster, remove the inserts, jet the carb right. The inserts make the carb smaller!

jetting is no prob the bike runs great tops out about 130 flat out

this is just a how far can we go deal nothing else

we would realy like to see 150 before the spring nationals

and the inserts do work well at top end

Well, you sound like you have you feel you have a handle on what you want. Best of luck to you.

hey guys need a little advise:banghead:

built an 03 yz250f .

it has the following mods high compression piston,major porting,huge cams,sick fast intake inserts(before and after carb)

the bike is a toy my son and i are riding around the yard we've been riding it with stock pipe

that was not right so we got the fmf powerbomb header,mid pipe,and the factory 4.1

how big of a carb can i get for this monster

Wow, so you can reach 130mph on a YZ250f, in your front yard. That's a big yard.

What, do you have it geared 15/42 or something??

That's pretty impressive. :smirk:

jetting is no prob the bike runs great tops out about 130 flat out

this is just a how far can we go deal nothing else

we would realy like to see 150 before the spring nationals

and the inserts do work well at top end

35-40 hp is NOT going to reach 150 mph. I don't believe you've hit 130 with it either. I'm not sure I would even believe 100.

And even if that was enough power to push a wheeled brick (aerodynamically speaking) through the air that fast...on knobbies, with that tall chassis and short wheelbase? That would be absolutely terrifying to ride.

I am hoping he means KMH..........

I am hoping he means KMH..........
We still use mph down here in Florida...:smirk:

If the jetting is good, why new carb?

If the jetting is good, why new carb?
A bigger carb (within reason) will increase air flow at higher rpms, increasing peak horsepower. This is assuming the cam timing, porting, exhaust, etc can support additional air flow.

In this case, he's barking up the wrong tree. Without some serious (IE expensive) engine work, the YZ250F won't handle much more carb than what it already has. And it will NEVER hit 150 mph with ANY amount of work. It won't do 130 either for that matter...

Only (2) posts to date.

TROLL ALERT.:smirk:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now