boring carb

[quadracer707]

Ok Guys true yfz 450

I put on post a while ago my mods
13-1 piston
complete new valves, springs lifters
Hot cams all around

Port & polished to the max

last post average H.P. was 52 -53 with stock carb with 175 jet

Now i want to bore out carb from 41mm to just under 43mm like 42.8mm. What kind of increase in H.P. would i gain, & ere should I start with jetting. Also do I have move the needle to somethimg different. ALL INFO much appreciated.

Thanx Wade

[buck naked-r]

heres what i got from it

and i did the center ring myself

http://i118.photobucket.com/albums/o101/buck450/2006_0227Image0001-2.jpg

[quadracer707]

Thanx,

about 2 xtra HP & more tourqe. Did you have do do major jetting?

[buck naked-r]

yes,jetting was and still is a problem for me,but i think its the pipe&intake combo thats causing my jetting issues.

but you will have to jet UP on the main after boring it

[quadracer707]

check pm, r u doing this for a yfz 450??

[buck naked-r]

Originally posted by quadracer707
check pm, r u doing this for a yfz 450??

the dyno above is for a trx,but ive done 3 yfz's also....after they saw the gains i got from it and we get it done for $75

[fast2007]

PORTED/POLISHED TO THE MAX.. :( Is that good?? Thats a NO NO can U say Velocity?? Not trying to be a smart butt..Im just telling u bigger isn't always better, really never is...

[yamahaman623]

i have a yfz with some goodies done to it. i want to drag 300 feet. i heard it takes from the bottom and i don't want that so pm me with more info.

[fastford]

When your testing this make sure to get back on the same dyno!! Every dyno will give you different numbers. Use it as a starting point and see what gains you get.