what octane gas?

[emaxxjeremy]

i have an 05 300ex with only a k&n air filter, no other mods. it really doesnt run that well. my brothe has an identical bike and it runs way better, and his is totally stock.
i do run 93 gas. would the k&n filter hurt the fuel mixture that much? or should i be running lower octane fuel?

[Chino]

Originally posted by emaxxjeremy
i have an 05 300ex with only a k&n air filter, no other mods. it really doesnt run that well. my brothe has an identical bike and it runs way better, and his is totally stock.
i do run 93 gas. would the k&n filter hurt the fuel mixture that much? or should i be running lower octane fuel?

gas has nothing to do with this, sounds as if your jetting could be messed up, as for the k&n air filter, i would ditch it for a foam filter, I'm not a big fan of k&n's after i've saw what they can let into your intake and engine..

[hondarider2006]

Sounds like a jetting issue. Your K&N is letting it breath better, which makes it run leaner. Go up a size or 2 on the main jet and see what happens.

[bwamos]

Yep. what he said.

The 300ex's stock are borderline lean (for emmisions reasons I'm sure), changing the filter will take it over the edge and you will lose a signicant amount of power. Go up 2 sizes on the main jet. You should still be fine on the needle and air crew/pilot. Just adjust the main jet up.

As for fuel. The 300ex stock piston will run on any pump fuel. Regular to Premium. It has a very low compression. Premium is probably a little better just for the extra detergents, the octane doesn't matter on a stock 300ex.

[pinky93]

Remember that all octane does is slow down the flame front to prevent detonation. This is more critical with high compression, more ignition advance, etc.

You just need to re-jet to get your air/fuel mixture back in line.:D

[emaxxjeremy]

thanks for the help guys.
i think i am going to go ahead and ad a pipe while i am having to rejet anyway.

[kd5sfq]

How often do you clean your K&N? A clogged air filter will make an engine run crappy... So will crud in your fuel tank... Clogged jets... Valves out of adjustment... A bad spark plug... Water in your fuel... The choke being on...

[cals400ex]

the first thing i would do is adjust the throttle cable. ;)

[pinky93]

Originally posted by cals400ex
the first thing i would do is adjust the throttle cable. ;)

First things first.....:D