300ex sounds and feels abnormal

[willjoe86]

A few days ago my friends were riding my 2001 300ex around and after a while I took it for a spin and it didnt sound right or feel right. It seemed to have lost power and its kind of hard to explain the sound - each detonation sounds kinda hollow or something...?

A few weeks ago I installed a K&N filter and jet kit - I dont know if this might have anything to do with it.

Could this be a sign of loss of compression? Remember, its a 2001 and its never really been ridden hard, or raced.

I was also thinking of overheating - I dont know what the effects of overheating are...

Any ideas I would really appreciate
Thanks everyone!
Will

[4TraxRider]

Sounds like your a little lean. My brother's did that until i rejetted it.

[300exazzkikr]

do a plug check and see what's goin on in there.

[willjoe86]

thanks everyone
I didnt think it was the jetting since it was working fine (or I thought so) for a few weeks.
It also is smelling funny...maybe this has something to do with it.
Will

[Diedrich]

yeah i say its the jetting man..need to check that out

[willjoe86]

So if it was the jetting, it would probably be a combination of the needle and the main jet right?
thanks
Will

[cals400ex]

it is probally the needle or mainjet if is is running bad from 1/4 to full throttle. look at the plug and see what it looks like.