04 yz250 top end

[bush ranger]

G'day Guys,

I have a 04 yz250 and was wondering if any one has got more top end power out of these engines. I dont want to loose any bottom end power. Will porting help? If this helps does any one know a good engine porter in Australia.

Any help appreciated.

[Satch0922]

what mods have you done to it so far?

You always have pipes, reeds, porting and .......,.big bore kits!

[Blue 250]

You could run a Boyesen Rad Valve without the spacer, that is supposed to give a lot up top. But it does take a little bottom. I've heard that just by running either a FMF Power Core 2 or a Pro-Circuit 304 silencer gives some gains up top also. I was running a FMF Titanium 2 which is the same as the shorty with the stock pipe for awhile and gained tons of bottom and mid but I didn't lose any topend at all.

[khyz250]

I have an '04 YZ250. I put on an FMF Fatty and Boyesen Rad Valve. It gave it more noticable throttle response and top end. I also jetted my bike pretty well. I went one down on the pilot from a 50 to a 48 and moved the clip up one position on the needle. That also gave it more pull on the top.