2008 yfz 450 flat spot right after idle

Yamaha

Having a problem with my YFZ450. I just installed a WB aluminun pro full system. Rejetted to a 168 main jet 145 pilot and #4 position on the needle. When I open the throttle fast in neutral the quad backfires and stalls. I removed the air box lid and added a WB air filter. And hint on what could cure the problem? Appling the throttle slowly, bike works perfect. Also idles perfect. only quick snaps of the throttle.

Sounds like the typical "bog". Your jetting looks to be on par for your mods as well. From my own personal experience, what you need to do to fix this is the "o-ring mod". It was the last piece to the puzzle to completely eliminate the bog for me. Its often overlooked.....people usually put the AP cover on it and think its fixed, but still occasionally find the bog again.

This will cure it, take my word. Props to the guy who made this video as well...

http://www.youtube.com/watch?v=f64kwSuggO8

Thanks I will do that tomorrow I hope that takes care of it.

Thanks I will do that tomorrow I hope that takes care of it.

Post back up with your results. If your jetting is close, it will eliminate the bog totally. I have the feeling you will be pleasantly surprised. :bonk:

Wow the bog is gone! Decided to go with a A/C o-ring though had a couple left overs in my tool box. Much better.... Thanks for all the help.

:bonk:

can anyone tell me how to do this the vid. was removed by the user im having same issues thanks.

can anyone tell me how to do this the vid. was removed by the user im having same issues thanks.

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