new to 4 stroke..06 yz450

[pink63impala]

just traded my 2 smoke for a yz450.

gew questions..

it has a white brother exhaust system. i notice when i give it some gas ,sometimes i see a blueish flame shoot out the end.also,when i ride it,say 2nd or 3 gear ,and let off the gas,i get a pop or backfire sound from it? is any of this normal?also i sometimes see blackish smoke when i rev it up,like to much fuel?the guy said i he changed the jetting and the needle position, but i havent been into it yet or know what setup to run. thanks

[pink63impala]

[diegox450]

It's a little on the rich side... nothing to worry... The flame is normal. My WR450 sometimes pop ups 1 foot flames when riding at night. The pops could indicate a lean condition... but you say that you see black smoke when revving it... it's contradictory...

BTW Nice looking bike, congrats!!!

[grayracer513]

It's a little on the rich side...

Lean, usually. Not much to be concerned over, though:

https://www.thumpertalk.com/forum/showthread.php?p=3710599#post3710599

[pink63impala]

Lean, usually. Not much to be concerned over, though:

https://www.thumpertalk.com/forum/showthread.php?p=3710599#post3710599

thanks

[REDBULLRICK]

on my dads 06 yz450 , we put a 45 pilot and a 170 main and moved the needle clip to the 4th one no more popping or backfire

[live4speed]

popping usually means lean...180 main and 48 pilot...granted my bike had a stock pipe, but the stocker is 06 was damn near wide open anyway, and with those specs i got no popping, acceleration was greatly improved, throttle response seemed better, and last but not least...the bike would start!!! with the stock jetting i had the worst time getting that bike fired up...

[hillclimbguy]

Nice bike. You made a good choice. Our bikes take a pounding and last. I dont think you'll be sorry.

[grayracer513]

I own two '06's, and a 180 is way too big unless you're maybe ice racing at sea level. I run a 168 with DRD exhausts from sea level (and below, actually) to 3500 feet with no problem.