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

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.

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.

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

What about checking that headers are torqued to spec? 

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

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.

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.

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

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.

The stripped header bolt sounds suspicious.......any gasses escaping.

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

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.

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

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

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.

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

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.

Is there anything i could do without taking the carbs off the bike? I dont think i have to know-how to do that

I'll let others chime in that are more expert on carbs than me.