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Main Area => General GS500 Discussion => Topic started by: punisherlp on April 03, 2013, 03:30:40 PM

Title: Popping sounds from exhaust
Post by: punisherlp on April 03, 2013, 03:30:40 PM
I have recently run into a problem with my exhaust and engine having a popping sounds when at idle.
Recently I changed the spark plugs to iridium and the bike ran fine even during a long trip, then the other morning it turned it on and there was a bunch of popping noises coming from the exhaust and the bike felt rough and shaky at idle. Originally I thought it could be a fuel issue so then i filled the tank with new gas and half a bottle of seafoam. Nothing seems to fix the issue. If anyone has had the same problem i would love to hear how to resolve the issue.

Thanks


and here is a video to help show what im trying to describe
http://www.youtube.com/watch?v=xEohNubT3Sc&feature=youtu.be
Title: Re: Popping sounds from exhaust
Post by: adidasguy on April 03, 2013, 03:32:43 PM
Loose spark plug wires? Caps loose on the wire or wire loose in the coil? Try giving them a clockwise turn to insure they're making good connection.
Title: Re: Popping sounds from exhaust
Post by: Zethioth on April 03, 2013, 03:35:54 PM
My bike pops a lot too. I used to think it was from the exhaust but after listening closely it's coming from inside the exhaust next to the header.

Popping is simply unburnt fuel burning in the exhaust/muffler. Remember, the GS comes stock very lean. A rejet would most likely fix this problem.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 03, 2013, 04:25:44 PM
The previous owner had the bike rejetted and it had been running fine for the last six months, so im hoping to avoid doing a rejet. There is one loud pop from the header area when the bike starts then only a popping sound like in the video continues

I might try and put the old spark plugs back on and see if it fixes the problem
Title: Re: Popping sounds from exhaust
Post by: Scoz on April 03, 2013, 05:10:19 PM
What about checking that headers are torqued to spec? 
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 03, 2013, 06:56:15 PM
Three of the four header bolts seem to be in spec, the fourth is stripped and needs to be replaced which i was planning on doing soon
Title: Re: Popping sounds from exhaust
Post by: Zethioth on April 03, 2013, 06:56:48 PM
Quote from: punisherlp on April 03, 2013, 04:25:44 PM
I might try and put the old spark plugs back on and see if it fixes the problem

If that fixes the problem, look into getting some new Iridiums with a wider gap. Do not gap the plugs you have.
Title: Re: Popping sounds from exhaust
Post by: john on April 03, 2013, 10:13:04 PM
If it pops at throttle roll off after a rejet, especially after a rejet then it is normal.  But at isle, sounds more like electrical like a spatk plug is fouled and not working properly, or bad spark plug wire or corroded connection.
Title: Re: Popping sounds from exhaust
Post by: m_melen on April 03, 2013, 11:06:24 PM
Don't quote me on this, but if you think it is a mixture problem you could let it idle and play with the choke to see if changing the amount of air in the mix affects the popping. Should at least let you know if your mix is the problem
Title: Re: Popping sounds from exhaust
Post by: adidasguy on April 03, 2013, 11:32:36 PM
The choke on our bikes is not a true choke. It makes it richer by allowing fuel in through a bypass passage. It doesn't "choke" the air. We call it a choke. Manuals refer to the "starter" circuit.

Running with the choke on would be richer and if there is a difference, it would indicate you might have been running too lean.
Title: Re: Popping sounds from exhaust
Post by: fetor56 on April 03, 2013, 11:48:52 PM
The stripped header bolt sounds suspicious.......any gasses escaping.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 04, 2013, 09:25:32 AM
i was going to replace the header bolts and gaskets this weekend when i repaint the exhaust. I couldnt feel any gases escaping now but i didnt really want to put my hands too close to feel is there was air escaping.

Also going to try getting regular sparks and seeing if it fixes the problem, I was looking at the ones i pulled out and they seem rusted and old and dont want to put them back in
Title: Re: Popping sounds from exhaust
Post by: fetor56 on April 04, 2013, 02:23:13 PM
Quote from: punisherlp on April 04, 2013, 09:25:32 AM
i was going to replace the header bolts and gaskets this weekend when i repaint the exhaust. I couldnt feel any gases escaping now but i didnt really want to put my hands too close to feel is there was air escaping.

Also going to try getting regular sparks and seeing if it fixes the problem, I was looking at the ones i pulled out and they seem rusted and old and dont want to put them back in

A simple test method is putting a cigarette close to the gasket & see if the smoke is dispersed....non smokers to create smoke screw up some newspaper to a tight wick,light it then put it out.
I doubt the Iridium plugs are the problem(unless there the wrong ones) but u can replace & change back if necessary.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 04, 2013, 03:03:03 PM
I guess im just hoping the spark plugs are the problem since that was the last thing I did to the bike before it started acting funny
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 04, 2013, 03:37:49 PM
So i just tried a test i saw in a different post where i take each the boot of each plug off to see if the engine would still run
On one side the engine ran fine with no popping or strange noises but when i switched to the other side the engine wouldnt get over 1k RPM and die quickly but would run fine with choke. I was thinking of trying a compression test to see if that was the issue
Title: Re: Popping sounds from exhaust
Post by: adidasguy on April 04, 2013, 04:12:47 PM
Ah, the old Hillbilly Carb Sync method.
Yes - one cylinder is the problem. Could be carb or compression or something else. at least you now know which side of the engine needs attention.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 04, 2013, 04:42:49 PM
None of the auto stores here had the right adapter for the compression test, so now im not sure where to go. Unfortunately ill most likely have to take it to the local shop in town
Title: Re: Popping sounds from exhaust
Post by: adidasguy on April 04, 2013, 04:48:05 PM
One side is running lean. Most likely the carbs. Since choke makes it run, means lean. The choke doesn't choke. It makes it richer by allowing more fuel in through a bypass circuit called the "starter circuit". You might look at that carb first. Maybe that side needs the mixture screw tweaked a little. Maybe the pilot jet is dirty.
I would doubt it is compression based on  what you said about the choke.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 04, 2013, 05:03:05 PM
Is there anything i could do without taking the carbs off the bike? I dont think i have to know-how to do that
Title: Re: Popping sounds from exhaust
Post by: adidasguy on April 04, 2013, 05:17:47 PM
I'll let others chime in that are more expert on carbs than me.
Title: Re: Popping sounds from exhaust
Post by: Zethioth on April 05, 2013, 02:37:49 AM
You've got everyone here on the forum to help you take you apart, clean, and re-assemble carbs!

I always though it woulda been cool to do a live video feed whenever someone was working on their bike, then everyone could chime in. Lol  :icon_mrgreen:
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 05, 2013, 08:49:12 AM
I found a friend that has a good compression test kit so ill try that and narrow it down and make sure its the carbs before I tear into them.

I would do a video but since I've never done it before it would take a couple hours
Title: Re: Popping sounds from exhaust
Post by: dmoore on April 05, 2013, 09:42:50 AM
How does the spark compare from the good side to the problem side? You may have a coil going bad.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 05, 2013, 09:53:55 AM
I forgot to check that yesterday, thanks for reminding me. If it is the coil, how hard are they to replace?
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 07, 2013, 01:15:29 PM
yesterday i drained the carbs and everything seemed to work fine but then today i go to ride and there popping sound is there again but from the area between the carbs and the engine. And there is a significant knocking sound from the carbs
http://www.youtube.com/watch?v=msc2zSDGAF8&feature=youtu.be

Has anyone dealt with this problem before?
Title: Re: Popping sounds from exhaust
Post by: Suzuki Stevo on April 07, 2013, 01:41:16 PM
Quote from: punisherlp on April 07, 2013, 01:15:29 PM
sound is there again but from the area between the carbs and the engine. And there is a significant knocking sound from the carbs
http://www.youtube.com/watch?v=msc2zSDGAF8&feature=youtu.be

Has anyone dealt with this problem before?

If it "pops" and the engine kinda stalls (sounds like yours does from the video), the intake valves may be too tight. The popping could be the fuel/air mixture between the carb and the intake valve lighting off because the intake valve is not sealing (too tight). Once the mixture in the cylinder goes "bang", the leaking intake valve lets the flame get back into the intake track..this could be the "pop" you are hearing?   :dunno_black:
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 07, 2013, 02:08:47 PM
That makes sense, is there any way to test your theory? Im not really sure how to work on the carbs and valves. I ran each cylinder separately by taking the spark plug boot off, and there was no popping or knocking on either side, only when both cylinders were running
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 08, 2013, 01:00:37 PM
Went to the local shop today to see what they thought. The mechanic said it was dirty idle jets and that it would cost $200 and take three weeks to get the work done, sounds like im going to learn how to clean carbs pretty soon :woohoo:
Title: Re: Popping sounds from exhaust
Post by: mchollan on April 08, 2013, 06:16:02 PM
I had the same type of sound when I first got my bike.  A valve adjustment fixed it for me.
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 09, 2013, 04:58:19 PM
I hoping that the carb clean will fix it for me since this is my main vehicle and cant wait for the new valve shims to arrive
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 12, 2013, 07:44:09 PM
Just got done cleaning the carbs, and its not that. So next step in valve adjustment, is there a tool that i could buy at an autoparts store instead of the valve tool from suzuki?
Title: Re: Popping sounds from exhaust
Post by: punisherlp on April 25, 2013, 01:35:22 PM
Took apart the carbs again because gas was leaking from left carb, put everything back together again and it worked for a little bit. The ticking noise is much softer but now I also have a hanging idle and now when choke it on it lowers the rpms