GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: trend on July 25, 2006, 06:16:53 PM

Title: Exhaust goes boom
Post by: trend on July 25, 2006, 06:16:53 PM
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
Title: Re: Exhaust goes boom
Post by: The Antibody on July 25, 2006, 06:52:59 PM
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  8)
Title: Re: Exhaust goes boom
Post by: trend on July 25, 2006, 06:55:02 PM
I would say a backfire would be the correct word :)

I will still check my air box

thanks
Title: Re: Exhaust goes boom
Post by: trend on July 25, 2006, 07:06:33 PM
Hmm.. if i can find the airbox :/ I guess i need to go to my old place and pickup my HANS manual
Title: Re: Exhaust goes boom
Post by: The Buddha on July 25, 2006, 07:09:10 PM
Anti ... you're back ... whooo hoooo ...
They always come back ...
Cool.
Srinath.
Title: Re: Exhaust goes boom
Post by: annguyen1981 on July 25, 2006, 07:19:52 PM
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
Title: Re: Exhaust goes boom
Post by: Mandres on July 25, 2006, 08:06:20 PM
Quote from: seshadri_srinath on July 25, 2006, 07:09:10 PM
Anti ... you're back ... whooo hoooo ...
They always come back ...
Cool.
Srinath.

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

Title: Re: Exhaust goes boom
Post by: JamesG on July 25, 2006, 08:33:09 PM
"Boom" under acceleration is an intake backfire. If its not something screwy with the airbox. I would suspect intake valve clearances being off.
Title: Re: Exhaust goes boom
Post by: manns on July 26, 2006, 04:08:04 AM
Quote from: trend on July 25, 2006, 06:55:02 PM
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.
Title: Re: Exhaust goes boom
Post by: The Antibody on July 26, 2006, 05:38:02 AM
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  8)
Title: Re: Exhaust goes boom
Post by: trend on July 26, 2006, 11:03:13 AM
When I apply the throttle, Iget the backfire
Title: Re: Exhaust goes boom
Post by: natedawg120 on July 26, 2006, 11:08:40 AM
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.
Title: Re: Exhaust goes boom
Post by: trend on July 26, 2006, 11:10:15 AM
yeah, it does it after it is warm as well :/
Title: Re: Exhaust goes boom
Post by: JamesG on July 26, 2006, 11:20:29 AM
How old and how many miles are on this bike?
Title: Re: Exhaust goes boom
Post by: trend on July 26, 2006, 11:27:21 AM
year 2000 bike. 16k miles
Title: Re: Exhaust goes boom
Post by: JamesG on July 26, 2006, 12:37:18 PM
 When was the last time it had its valve clearances checked?
Title: Re: Exhaust goes boom
Post by: trend on July 26, 2006, 12:39:23 PM
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?
Title: Re: Exhaust goes boom
Post by: trend on July 26, 2006, 12:49:59 PM
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?
Title: Re: Exhaust goes boom
Post by: JamesG on July 26, 2006, 02:43:41 PM
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.