Big Bore jetting help

[bluebyu]

I just finished bolting on a 488 kit to my wr450. I know i'll need some jetting changes and i'm looking for some advice. I've done all the free mods and have a q2 pipe on it. I'm currently running a 48 pilot,obdut(03 wr) needle clip's 4th from the top and a 170 main. Everything else is stock.

Thanks :ride:

 

[SFO]

OK, I'll give this one a stab...
On the 2mm os 426 I went two sizes leaner on the main.
After having the 97mm dyno tuned that carb and jetting worked perfect on a donor 400.
You should be in the ballpark, don't be scared to go leaner on the main if it blubbers on the needle transition.
BTW, who's kit and what elevation do you ride?