exhaust pop pop pop

[Anonymous]

What's going on when I decelerate and I get a lot of popping noise out of the exahust? Much more pronounced when I'm using the gears to slow down. The bike is an 80 GS1000G with a Jardine 4-1 header.

Thanks
Ben

[Anonymous]

Do you have K+N's or Pods on it?
If so, then it could be normal. I have seen this happen in cars that have a good intake and aftermarket exhaust. I'm not sure of the exact reason why, but I think it has somthing to do with too much air being in the cylinder when you are slowing/reving down the engine. Its not a bad thing necessarily, it can just sound bad if you dont like that sound.
Maybe someone else in this forum can explane better?

[Anonymous]

The bike has a K&N factory replacement filter on it, but behaved the same way with a standard UNI foam filter.

I don't mind the sound at all, just wanted to know why.....

[Anonymous]

It's a mild flavor of backfire. It's likely caused by a lean condition. If your machine is otherwise good, a carb balance should clear it up.

It's bad to run lean, so you really should do something about it, and not ignore it.

[Anonymous]

actually, to be quite honest, I had this exact problem last week! Right after I had got my 750, i had cleaned the carbs, blah, blah blah, but had kept using the prime postion on the petcock(just cause).Anyway, one day after work, i was letting 'er warm up, when i heard a hissing sound, turns out this whole time i had an atmosperic vent hooked up to the petcock, and i was sucking in extra air, causing my satanic backfires :twisted:
#3 hose is vacuum-1,2, and 4 are atmospheric vents on the topside of the carbs

P.S.: I've got a V&H 4-2-1 on mine....take the baffle out of yours....if my extrodinarily long story/solution does'nt work, you'll at least have really cool flames shooting out of the exhaust for everyone to see, when you back off the throttle(whew...that just winded me )

[AOD]

bawh bawh bawh bawh...it's kinda cool actually.

my 550 (pods and 4-1) pops under decel from ~6000+ RPM and up.

no problems with it for me...if you pop on decel much lower than that, i'd be worried about a lean condition. how do your plugs look?

~Adam

[Anonymous]

It pops on decel all the way down so based on what you all are saying I'm running lean. Next question is what are the steps to correct this? Do I need to rejet the carbs or just make adjustments? Sorry if that's a stupid question but this is the first carbureted engine I've ever worked on, all my experience is with fuel injection.

Thanks

[AOD]

what would be good is to check your spark plugs to verify you are running lean. get the engine hot, go for a ride, and get it to decel down like you're saying. pull the clutch, stop the motor, roll to a stop, then check the plugs.

white = lean, as i'm sure you know.

i've noticed things like an exhaust leak can amplify or cause backfires in the exhaust as well.

~Adam

[KEITH KRAUSE]

It pops on decel all the way down so based on what you all are saying I'm running lean. Next question is what are the steps to correct this? Do I need to rejet the carbs or just make adjustments? Sorry if that's a stupid question but this is the first carbureted engine I've ever worked on, all my experience is with fuel injection.

Thanks

You may have an exhaust leak. Try re-torquing the bolts. Loosen first and then re-torque. You may have to replace the exhaust gaskets. Be aware that exhaust bolts can be stuck sometimes. Loosen/tighten bolts uniformly.
If it's carburetion and the intake is stock, then an additional 1/4 turn out on your mixture screws may help. Be sure you still have the stock airbox lid or you will need a jetting change or a new lid. A good carb synch may help and is needed periodically anyways. Ignition timing is important too.
Some popping is normal, but if it's bad and the above doesn't help, then you may have to service the carbs.

[Anonymous]

exhaust gasket replacing

82 gs1100e tried o replace the exhaust seals, how do you remove the old one? Thanks,

[Jethro]

tttjump Posted: Thu Feb 17, 2005 9:00 am Post subject: exhaust gasket replacing

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82 gs1100e tried o replace the exhaust seals, how do you remove the old one? Thanks,

I use a 90 degree angle pick to pull them out. If they are subborn, I use a thin, long screwdriver, put the blade as close to the inner gasket mating surface as possible, get as much angle as possible and tap the screwdriver handle with a hammer to pry behind the gasket. Don't worry about trashing the gaskets, you can't reuse them anyway.

[HiSPL]

Popping on decel can be caused by three things. A lean mixture, loose header bolts/exhaust gasket leaks, or an excessively rich mixture.

It would have to be really, really rich to cause the popping though, so for the sake of argument let's eliminate that one. Most likely culprit is your exhaust gaskets are leaking. They suck in fresh oxygen after the exhaust pulse races out of your head which provides enough fuel to have a small explosion in your exhaust pipe. If your baffle ever comes loose it could spit your muffler innards out into the street . It happened to me once.

[RJ]

Had the same problem with my 1100. Individual pods, header, etc. I cleaned and synched 2 sets of carbs, bolted up a Dyna S ignition, new exhaust gaskets, still popped. Finally replaced the old ratty Kerker with a new Vance&Hines header, no more popping. The old header didn't have any visible holes but did have some rust between the collector pipes.

[Jackrp]

Re: exhaust pop pop pop

What's going on when I decelerate and I get a lot of popping noise out of the exahust? Much more pronounced when I'm using the gears to slow down. The bike is an 80 GS1000G with a Jardine 4-1 header.

Thanks
Ben

I have a Vance and Hines on my 850 with stock air box, and the plugs say its running O.K. and when I snap the throttle closed it does the GREAT pop pop sound I love it, my 1000G, and 550MZ with a kerker and Bassani both do it too, been doing it since 1982, and they are running fine.Enjoy