I have a 99 VStar and it backfires something awful. Carbs have been worked on and still backfiring. The original owner installed cobra pipes. My brother says this is probably the problem. Does that make sense?

Yes, it makes sense. You've got an imbalance of air to fuel ratio, factory pipes are specifically designed with that ratio in mind. But if it wasn't doing it before and just started, my guess knowing the history is an exhaust leak. The other possibility is a dirty/wrong jet. You said the carb was worked on, was the jet replaced? Was it replaced with correct jet? Along those same lines, check your fuel filters

Ok. Thanks. Is this something I can do myself or would I be better served taking it to a shop?

Is it backfiring all of the time or just on decel (with clutch not engaged)? My KLR did the latter after a new pipe and I was able to adjust the air/fuel screw to fix it after some research.

Accelerating or decelerating. Much worse on deceleration but it does it either way.

I'd google the bike model & pipes that were installed. Usually there are recommended jets and you can do it if you're comfortable taking the carbs off and swapping the jets. Usually just need to get the bowl off of the bottom, unscrew old ones and replace w/ new ones.

I'd give the carbs a good clean while you have them off.

Definitely need to install a jet kit. Did the p/o change the air filter as well?

It has been changed.

Reload8098 said:

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It has been changed.

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I guess I was as clear as mud. Is it the stock filter or an aftermarket high-flow filter? The latter will also affect the f/a ratio. Pull the carbs, check main and pilot jet size. Note the mixture screw setting (# of turns to lightly bottom out). Do some research on the yammy boards to see what jets you need and for a base setting on the mixture. Make sure everything is clean in the carb body....especially all passages. Completely disassemble the carb and remove all rubber parts before hitting it with carb cleaner. Then soak the body overnight in a can of cleaner.

Are they slip-on for full exhausts? I have an 08 1100 classic with full Cobra Speedster Slashdown exhausts. When they were installed the shop changed the jet screws and re-synced the carbs. Don't remember if they did any other adjustments. You can go here for more info or this forum for advice.

https://sites.google.com/site/vstar1100kb/home/

https://www.starbikeforums.com/

Full exhaust. I don't have the skill level or the time to get into that kind of work on the carbs so I'll have to take it on the $,$$$ chin, damnit. I'm in sales and travel a great deal so personal time is family time. Going on a trip with an Aggie buddy and some other guys for a week and need to get the bike ready. Really appreciate the help!

Reload, I don't either, guess MC shops like folks like us lol. Hopefully you can find a shop close to you or perhaps a fellow rider friend that can adjust them. I have two shops here in Houston that I alternate between but can't help with where your located. Good luck.

Reload8098 said:

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Full exhaust. I don't have the skill level or the time to get into that kind of work on the carbs so I'll have to take it on the $,$$$ chin, damnit. I'm in sales and travel a great deal so personal time is family time. Going on a trip with an Aggie buddy and some other guys for a week and need to get the bike ready. Really appreciate the help!

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Where ya located?

Knoxville