[04`yfz450]

went out and bought my new FAT BOY 4 pipe (duncan racing) they gave me a bunch of different jets the quiet cap and sparky for $535.00 OTD.(good deal saved about $70.00).anyway they recommend a 180 main ,45 pilot,and 3rd clip on yz needle. with my stock pipe(baffle out) i was at a 165 main,45 pilot(2 turns out) ,and 3rd clip on yz needle.(i have the cam mod and K&N).i was thinking a 48 pilot,180? main,and 4th clip on yz needle??? what would you guys recommend? i`m at sea level. i still have to put on the 15T sprocket .after that what else is there to do to get more power?

 

[YFZ_53]

:woo let us know the power difference :rock

 

[rtyfz450]

did they recommend the jetting for a stock yfz with the pipe or with the current set up that you have? If you haven't already, i would ask them what they think would run good with your current set up. try it first because i think duncan knows their stuff and I have seen many of their proven race bikes in action and wow they are fast. If it doen't work good for you then I would go with the higher pilot jet but i don't think that it is nessesary because I am sure duncan has done r&d on the jetting

 

[XtremeYFZ450]

I have done the followig mods:
Yoshi headers
Yoshi tri oval pipe
K&N with adapter
modified air box

I have not ridden it yet and have not jetted it yet but the settings that were recommended to me were:

180 main jet
45 pilot
1 clip up on needle

PM me if you get yours done before I do and let me know how it goes.....

 

[pahrump]

With each of your setps XtremeYFZ, and '04yfz, I would say 45 pilot maybe 48 pilot (I would try a 48, and 1 turn on the screw), 180 main, and 4th clip on the GYTR (YZ) Needle or 6th clip on stock needle.

And Xtreme you really should do trhe cam mod also you will for sure feel the power increase

 

[CODY ANDERSON]

:re

 

[TwiZteD]

how long does the cam mod take and what are the power differences???

 

[pahrump]

Probably take you like 45min to 1 hour very easy and very worth it.

Some say 2-4 HP gain with it.

I am very happy I done it to mine, me and a buddy went to Dumont last Tuesday and I had done the cam mom, baffle out, lid off and rejet, he had the baffle out lid off and rejet we weigh the same and I was pulling him by like 2-3 quads on comp. We switched bikes and the same result.