08 WR450F Jetting

I just bought a 08 wr450F and installed the dealer AIS kit which included the blockoff plate, jet needle new pilot, main (175) and air jet and leak jet. I also took out the restrictor in the exhaust and removed the grey wire.

Problem is that it won't run on the top end. Great up through mid range, put past that, engine just sputters. Any ideas?

Congrats on the new bike! Don't want to make any assumptions here - did you remove the "binoculars" or "snorkel" from the air box (i.e. open it up so it can breathe)?

I just bought a 08 wr450F and installed the dealer AIS kit which included the blockoff plate, jet needle new pilot, main (175) and air jet and leak jet. I also took out the restrictor in the exhaust and removed the grey wire.

Problem is that it won't run on the top end. Great up through mid range, put past that, engine just sputters. Any ideas?

My '07 came with a 162 main. I put the JDJetting kit on and the main went to a 168 and the pilot to a 48. I think the 175 is way too rich hence the sputter after 1/2 throttle. Check out the sticky's at the top of this forum. They have what other people are running as far as jetting and other mods.

Congrats on the new bike! Don't want to make any assumptions here - did you remove the "binoculars" or "snorkel" from the air box (i.e. open it up so it can breathe)?

Yes. Airbox stuff is removed. I assumed the dealer kit would have the jets dialed in, but I guess the 175 main is too much. I may try putting the stock main back in and leave the pilot (a # 50) and see how that goes.

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