Jump to content
Sign in to follow this  

03 yzf 250 hot rod help

Recommended Posts

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

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites
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:

Share this post


Link to post
Share on other sites
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.

Share this post


Link to post
Share on other sites
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...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

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

Reply with:

Sign in to follow this  

×