Exhaust goes boom

[trend]

After sitting for more than 20 seconds, when I try to get going on my motorcycle, sometimes the throttle feels slow, and then I hear a boom out of my exhaust.. and then I accelerate like normal.

I just had to adjust my idle screw.. maybe the above problem is the reason I had to?
Any ideas why I am having the lack of power then a boom?

thanks

[The Antibody]

check your airbox? My brother once had a mouse nest after a winter under the cover.

But really... a boom under throttle? or a backfire?

  -Anti 

[trend]

I would say a backfire would be the correct word

I will still check my air box

thanks

[trend]

Hmm.. if i can find the airbox :/ I guess i need to go to my old place and pickup my HANS manual

[The Buddha]

Anti ... you're back ... whooo hoooo ...
They always come back ...
Cool.
Srinath.

[annguyen1981]

Airbox.  Under the tank.

Depending on your year, you might need to remove the rear plastics near the front (not the whole thing).  Then remove two screws holding the rear of the tank.  slide tank towards rear a bit and lift up.  Viola!  Airbox

[Mandres]

Anti ... you're back ... whooo hoooo ...
They always come back ...
Cool.
Srinath.

Yea man, post up some new pictures of that badass paintjob.

[JamesG]

"Boom" under acceleration is an intake backfire. If its not something screwy with the airbox. I would suspect intake valve clearances being off.

[manns]

I would say a backfire would be the correct word

I will still check my air box

thanks

Did you let your bike warm up? Let your engine warm with choke for a minute.

[The Antibody]

Yes, airbox requires you to remove the two bolts at the rear of your tank. black box. Anyway, if it is a backfire when you release the throttle, a lean fuel mixture is the most probable cause. Re-jetting helps that problem.

Under throttle?... James G is better at that.

  -Anti 

[trend]

When I apply the throttle, Iget the backfire

[natedawg120]

My bike will do that if it isn't warm.  If you start it then try to take off shortly after, say less than a minute or three, I get that behavior.  Let your bike warm up a bit and see if it continues.

[trend]

yeah, it does it after it is warm as well :/

[JamesG]

How old and how many miles are on this bike?

[trend]

year 2000 bike. 16k miles

[JamesG]

 When was the last time it had its valve clearances checked?

[trend]

no clue :/ just got hte bike 200miles ago.

Is this hard to do? (If you don't know how)?

maybe I should take this to a mechanic and get that checked out?

[trend]

something wierd though I just noticed after jumping on it... After it has been sitting.. I crank it up. pull the throttle down 20percent or so. and it goes from the idle 1k rpm, to 2k rpm, to 1rpm, to 2rpm, then after a second or two of this, goes up to the normal RPM (where the it should be at the this throttle position.. ) which is 5k rpm or so.

I can let go of the throttle, and the above will repeat.

I diddn't hear any backfire in the 30 seconds or so (cold engine).

ideas?

[JamesG]

Could be alot of things, from valves being off to just an intake boot being loose. This is one of the more annoying "out of tune" problems GSs get. I would say if you don't have experiance with working on bikes and don't want to futz with it, just take it to a shop.