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2006 Vstar 1100 classic
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Discussion Starter #1
Just bought a “new to me” 06 Xvs1100 from a dealership and about a month after riding I’m starting to have carburetor backfires and pops from the exhaust.
It has a stock air box and an aftermarket exhaust system. I seem to get really low fuel mileage too. I know that I should some tuning to the carburetor but what other issues would cause this?
 

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2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
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725 Posts
Welcome. Could be something as simple as bad spark plugs.
 

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Super Moderator "Loose Nut"
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You not knowing the history of the bike, might be some gunk in carbs. I would start with a few tanks of Seafoam treated fuel. It's a cost effective way to clean carbs with minor issues. Also noticed this was your first post. If you post an introduction in the New Member section we can get to know you and your bike.

 

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Just bought a “new to me” 06 Xvs1100 from a dealership and about a month after riding I’m starting to have carburetor backfires and pops from the exhaust.
It has a stock air box and an aftermarket exhaust system. I seem to get really low fuel mileage too. I know that I should some tuning to the carburetor but what other issues would cause this?
What the others said. Sea foam spark plugs and make sure the carb is adjusted right. I would go back to that dealer and talk to them. They might try to make it right. Such as plugs and the carb thing. If not then they didn't need your continued patronage.
 

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I would make an educated guess that someone put aftermarket exhaust, everyone told him to rejet it and he had no idea what he was doing . then he playing with the mixture screws, got it totally out of sinc, traded the bike in and the dealer didn't go through it because he rode it there and they wanted to sell a bike.
Just a guess, let's see how this plays out.
 

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2006 Vstar 1100 classic
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Discussion Starter #6
I’ve already checked the plugs and ran seafoam through the carbs. Thanks for those suggestions.
@Jspree I think that is exactly what happened. When I got the bike from the dealership they said that the guy had carb work done when he traded it in and I bet that’s what happened.
 

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A tell tale sign is the color of the exhaust. If they are blue, it's often times a mixture (jets) issue. You could also have vacuum leaks commonly caused by the boots on the carbs. I have a 'new to me' 05 and it consistently gets 50mpg as a reference.
 

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2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
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I re-read your original post, and it does sound like something has changed. It may help to try and recap:

Did something happen just before the popping began? (Different fuel, change of tone/sound, harder to start,rain, change of performance etc)
Have you measured your fuel consumption? If yes, has it deteriorated or stayed the same?

If the carbs have been messed with, it could even be a main jet not secured properly that has unscrewed itself. An ignition coil on its way out, or a cracked spark plug cap, can cause misfires. A leak in the exhaust will also easily cause misfires. There are virtually endless possibilities.

Personally, I would begin with a tune-up. Check valve clearances, spark plug gaps and colour (should be the same for both), condition of the caps, carb sync, air filter check, all seams in the exhaust. Also check that the clamps holding the carbs to the intakes and the clamps holding the air filter tunnel to the carbs are all tight and the interfaces intact. Check intakes for cracks. If you can, checking compression never hurts, just short the spark plugs while cranking to prevent any possibility of hurting the TCI. Only then would I strip the carbs, if I found nothing else to be off. YMMV.
 

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Just bought a “new to me” 06 Xvs1100 from a dealership and about a month after riding I’m starting to have carburetor backfires and pops from the exhaust.
It has a stock air box and an aftermarket exhaust system. I seem to get really low fuel mileage too. I know that I should some tuning to the carburetor but what other issues would cause this?
Thank you for bringing us this issue. I am also having the same issue and will try some of the suggestions made here.
 

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One thing unrelated that i will warn you don't ever use the throttle to start only the enricher. The tps will change the timeing to what it would be when running and kick the motor backwards and ruin the starter clutch which is expensive to replace
 

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2001 VStar 650 Classic
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I seem to get really low fuel mileage too. I know that I should some tuning to the carburetor but what other issues would cause this?
Low fuel mileage is a sign of a bike running rich. I've seen this a few times.

The popping from the pipes could be caused by a muffler leak.
 

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Ok, here is my train of thought. When he got the bike it had had carb rejetted for aftermarket exhaust. It set at a dealer for a couple months , so the gas in the carb shelaced, not bad but some. Now he has been riding for a month , new gas cleaned that little bit of shelac out of the carb and it is too rich from being over jetted.
Quick story, I had a friend running a Suzuki, it was running lean, so he drilled the carb and adjusted it out. Then someone on the forum he was on said " run some seafoam through it" so he ran seafoam, it cleaned out the carb real good and now his bike was running rich. He adjusted a dirty carb then cleaned it and now has a misadjusted carb.
In your case I would rebuild the carb, look at what size jets it has and jet it properly. sync the carbs and see how she runs.
 

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I often wonder why fuel choice is low on the response list. This all sounds like too high of an octane is being used. That should be eliminated 1st. Premium causes this since it’s designed around 11:1 or higher compression and this is a 9:1 compression bike.


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2006 Vstar 1100 classic
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Discussion Starter #14
So this bike has been kinda sketchy since I bought it. The first thing that happened to it was that the exhaust baffle was not properly installed so I had to take the exhaust off and fix the baffle problem. Then I noticed that the intake boots were actually switched around, so I switched them back to their proper position. I’m noticing that the front cylinder seems to be backfiring so I went ahead and ordered new exhaust gaskets too.
Thank you all again for the suggestions. I’m going to eventually open up the carbs and clean and rebuild them, so any helpful tips or videos of how to would be much appreciated!
 
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