my dilema

[mikewr450]

i have a 07 wr450 and after reading the sickies and post i thought that doing the ais removal and jd jetting kit would help out the bike. my uncles has been riding and racing for 30 years. he has a 08 klx450r and he left the ais on and said that the backfire on decel is partially because of the pump gas and that by running 100 octane it would partially fix the problem. so my question is what kinda gas is everyone running? i also did the air box removal and exhaust baffle mod. what if i just get the new throttle screw and dont re jet? sorry for long post

[KennyMc]

I run pump premium in all of my bikes. I did all of the mods before I ever even rode the bike so I couldn't tell you about the differences.

[SJMC_DON]

Popping on de-cel is because you're jetting is lean ... I run 92 octane and never have backfiring on decel....

My 07' has all the free mods, AIS removal kit with 172 main vs. 175 supplied with kit. I ride 50 - 75 deg, 0 - 5000+ feet and rarely experience performance issue related to the current jetting config.

The bikes come set up too lean:prof:

[dustinw]

i have a 07 wr450 and after reading the sickies and post i thought that doing the ais removal and jd jetting kit would help out the bike. my uncles has been riding and racing for 30 years. he has a 08 klx450r and he left the ais on and said that the backfire on decel is partially because of the pump gas and that by running 100 octane it would partially fix the problem. so my question is what kinda gas is everyone running? i also did the air box removal and exhaust baffle mod. what if i just get the new throttle screw and dont re jet? sorry for long post

The GYTR de-restriction kit costs $40 and comes with the short throttle stop, jets you need, the AIS removal bits, and instructions. Works great for me on my '07. I think if anything it's a tad rich, and I had to set the needle clip to the very top of the needle (instructions have you set it at the fourth slot from the top) to get it to quit stumbling at 1/4-1/2 throttle.

No popping on decel running 92 pump fuel, and that is the only mod I've done to the engine. Running 100 octane will just net you less HP in your bike, so why bother.

[mikewr450]

The GYTR de-restriction kit costs $40 and comes with the short throttle stop, jets you need, the AIS removal bits, and instructions. Works great for me on my '07. I think if anything it's a tad rich, and I had to set the needle clip to the very top of the needle (instructions have you set it at the fourth slot from the top) to get it to quit stumbling at 1/4-1/2 throttle.

No popping on decel running 92 pump fuel, and that is the only mod I've done to the engine. Running 100 octane will just net you less HP in your bike, so why bother.

how will running better and higher octane fuel make the bike have less hp?

[dustinw]

how will running better and higher octane fuel make the bike have less hp?

Higher octane != better fuel

It resists detonation better, but by doing so it has less energy per given quantity of fuel. Ounce for ounce the higher the octane the less energy the fuel has. Oxygenated race fuel is a different story though. The only way you can leverage higher octane fuel for more power is by upping charge density (via forced induction) or increasing the compression ratio of the engine.

[mikewr450]

remember though you live in washington an i in so cal. i am no expert when it comes to gas but our highest octane is 91. and i am sure there is a ton of additives for all the smog s!!t we have to put up with. i am looking inot running the vp 100

[bicyclebob]

I have been running 100 octane low lead avgas ($4.88 a gal) and have had zero issues other than the exhaust smells cool.

[kskyles]

i run 91 octane from the pump. i've got a jd kit, TT AIS removal kit, and the free mods with an aftermarket exhaust.

no popping at all, and the bike runs well. the 100 octane is probably better fuel, but i just can't spend that much on gas when the bike runs well on the stuff from the pump.