Have you checked the intake seal ring? If its bad it will cause your issue

 

Did you ever fix this issue? I have the exact same thing going on with my 2003 883.

 

Rebuild and re-adjust your carburetor, and change all 3 intake manifold seals. There's no reason for the timing to change suddenly, it's pretty much set at the factory.

John

 

Carb cleaned/rebuilt with all new bits and pieces from rebuild kit thoroughly. Seals replaced. When I can finally get the damn thing to start it runs and idles like a dream. But starting it is the issue. Most of the time It just turns over, and over, and eventually just starts to backfire out the exhaust and cough out the carb. But once in a blue moon it will fire up and run amazing. I am so confused.

 

Are you sure the passages from your pilot jet, idle mix screw, and transfer ports aren't clogged? You need to take the jet and screw out, flush with carb cleaner and blast it out with air. Sounds like a fuel problem if it will start and run. Can you drive it?

Did you install the needle jet correctly? That's a common error.

Enrichener working correctly?

John

 

I blasted all of it with compressed air when I did the rebuild, and had the manual in front of me while I did the rebuild plus all the youtube videos to tag along with. The reason I did the rebuild and took it all apart in the first place was because it was giving me this issue to begin with. I will take it off and make sure everything was assembled correctly, but the problems were happening before the rebuild.

If I apply full choke when I try to start it the backfiring happens much sooner. I'm guessing it just floods everything and somehow the spark makes its way into the exhaust igniting all the unburnt crap. I've thought maybe it is indeed a timing issue as many people mention, or the valves are worn (bike only has 10k miles though). But then again, if that was the issue it would run like crap all the time when it finally starts? Am I right here? but it does not! It runs great when it finally starts....

Even though I had the issue before the rebuild, when I started it for the first time after the rebuild it started just fine (so I thought I fixed the problem). But once the carb was full again with fuel it started giving me the problems. Again, when I left overseas several months ago for work, I shut the petcock to off, got the bike to start and ran it dry, emptied the tank, took the battery off and placed it on trickle. When I came back I put everything back together, put fresh fuel. When I started it for the first time again, it came to life no problem at all. Like a bat outta hell. Rode it around all day. Then the next day I tried to start it same problem. Maybe it is the float? But in the same token, the float is lining up exactly how it is supposed to at the correct angle when I did the rebuild.

It also has new plugs, new coil, new plug wires as well because why not.

 

Not HD related, but when I have an engine that I suspect to be flooding or much too over rich, the test I use is to set the switch to OFF. Open throttle wide open. Turn the switch on and keep your hand near that switch. Then hit the starter switch. It should have enough air with the throttle disk full open to kick it off and make it go almost every time. If it does, obviously kill it to prevent over reving the engine. But that would be a sure indication that the float is spilling over fuel into the system even when the bowl is full. Float replacement and needle and seat replacement would be my guess...

Good luck. Let us know what you find.

 

. I agree , Pilot Air System , that's where I'd start looking.

 

I will let you know when I try it out. Thanks!

 

Also check your float level.