Uncorking stock WR450f pipe need to richen main?

[edareus]

I have a YZ silencer on the way for this bike but won't be here before the weekend. I want to know if I can uncork the stock muffler without rejetting for now? Or should I richen the main? Just got the bike Monday and I am going riding Sunday for the first time on this bike. ? I have already ground the throttle stop .25 of and inch and I am going to do the grey wire tomorrow.

[unkle_george]

It will backfire a little on decel and run a little hotter, but will run ok. Search for posts about breaking it in right, worth the effort. ?

Enjoy your new toy.

[RichieGoatGruff]

You'd be better off to rejet.....pilot and main will be needed. Up 1 on pilot and 1-2 on main.

[edareus]

Thanks, they gave me a couple of jets with the bike so I will go ahead and try them. Can't wait til Sunday!