Rocky Mountain Dirt Riders

So, the bike:

wr450
white brothers exhuast slip-on
air box mod
grey wire mod
changed main jet from 165 to 155
install A/F screw, set to 1.5 turns
ais removed
pro taper fat bar

I went to wild rose yesterday to check if everything was good. all i can say is DAMN!! this thing has balls.
Problem i notice though is when i am in higher rpm and let off the gas, clutch dis-engaged, i get alot of sputter.

1) what needle/jet needs to be altered to eliminate this?
2) this sputter means its rich?
3) from my owners manual, it looks like the pilot jet should be changed to lean/rich it out?
4) or the jet needle should be moved a clip to lean/rich it out?
5) also, i cant remeber if it is normal or not, but my throttle hand gets numb after about 20 min. is this normal or engine smoothness related?

THANKS!

Sounds like lean popping, a 155 main jet is probably too small for the current temps we are at, I would go back to the 165 mj a 40 pj a previous year YZ needle on the second or third clip from the top. Also disable the ACV valve on the left side of the carb, by removing the cover and flipping the diaphram so the pin points to the cover on reassembly. You will also have to play with the fuel screw on the bottom to get it right for varying temps. Also make damn sure that the AIS removal plugs are not allowing air to leak past them. Give that a try -- WR Dave

thanks dave... gonna do that stuff this weekend!

Dave's the man when it comes to getting WR's dialed in!

Helped me big time when i got mine.

the best thing I ever did to my bike was coss paths with WR_Dave. I love my bike See ya out there Chev

I have had my wr450 for three years and love it. This last weekend a new problem developed. When riding, sometimes it would not return down to a normal idle and would run at a very high RPM. I would spike the throttle and sometimes it would go back down to normal idle, but many times it would stay high.

It was inconsistent and it did it at different temperatures and different speeds.

Any suggestions on where to start would be greatly appreciated.

Thanks

Slide hanging up? Air leak on intake boot side?

I would pull the carb apart and check for any dirt or other foreign material that could be sticking the slide. Also check for frayed cable ends, worn linkage, etc. that could be getting stuck on the bellcrank on the side of the carb. Sometimes, removing, or flipping up the entire subframe is the easiest way to get the carb off.