I recently purchased an 04 Sportster 883XL to restore. I have done several things to the bike and almost have it right. I recently put an S&S Super E on the bike which made a huge difference but I am getting the occasional "burp" coming back through the carb at low RPM's and when accelerating from a stop. I did replace the "CKP" which was bad according to the Diagnostic code. This drastically improved the "burp" and cleared the code, but the occasional "burp" is still there. I am running stock exhaust on the bike, and it has been suggested that putting some slip on exhaust will both: correct the "burp", and will also improve my mileage (which is about 30 MPG right now). Can anyone tell me if new "slip ons" will help these 2 issues?
Also, I need to keep the noise level as low as possible because I have had 2 brain surgeries, so the noise level is a real issue for me, so I am hoping that a 1.75" baffle will be sufficient to overcome these issues for me.

 

No, I don't think slip-ons are going to correct your "burp" issue. At only 30 MPG, it sounds like you have a serious air/fuel mixture issue, as an 883 generally ought to be getting closer to 50 MPG or better. Did you have the carb properly tuned/jetted?

 

Y'know, every Sporty I've had burped through the carb once in a while, mostly when cold. I just ignore it.

 

Yeah I had a Harley pro set it up and install it. It did have the CKP code so I replaced it (which really helped". He let me pick it up and ride it, and told me it probably was the CKP, sure enough there was a code, there aren't any codes now. He told me to riches it which really cut down on the occurrences of the burp, and now it's very might happen 2-3 times in a 20 mile/semi urban setting. It runs great, but the burp and mileage still bug me a little. I would really be happy with 40-45 MPG though.

 

Your 04 should be due for replacing the intake manifold gaskets. A leaky gasket will cause the air/fuel mixture to go lean which will cause those burps and your "HD mechanic" may be trying to compensate for it by using carb jets that are too big, and that will send your MPG into the toilet.

 

He put a new intake manifold and gaskets on it with the carb, the S&S has its own manifold. I appreciate the comment though.

 

"Burps" or "Carb Cough" are a nature of the beast with carbed sportsters. Especially when cold. You learn to live with it.

 

Yeah I guess, the mileage is what's hard to live with, but thanks for replying

 

You have most definitely got a bad air/fuel mixture running through that bike. Your mileage should easily be at 50mpg+ as previously mentioned.

 

I have never gotten 50 mpg, but I get regularly 44-46. Sounds like an intake leak somewhere. the cough is usually a lean condition, and as has been said someone tried to compensate by going rich on the carb. Find your leak, and fix it. Then re-tune the carb. you will be good to go. Over on a more sportster centric forum there is a ton of info on carb set up. you can do it yourself.