Hello,
I have a 2002 fatboy that is stock except for a set of Vance and Hines Straigt shots. I am going to put a K&N air cleaner assembly on it and need to know if I will need to re jett the carb. Can I put the A/C on and then check the plugs for lean issues or is there another way to know. I used to wrench on my old Mach 1 years ago but have never tampered with a CV carb. Any advice would be greatly appreciated.

Thanks

 

You can sometimes get by with not rejetting if you drill the air mix plug and adjust the air down some. But, chances are you'll need slightly larger slow jet. I had a 45 and changed to a 48. Here's a link that talks about CV carbs.

http://www.harley-performance.com/index.html

 

oldgeezer has a good site for you to look at. I would say change the slow jet to a 46 or 48 and adjust the air/fuel screw out 2 1/2 turns from soft seat. The motor is usually lean from the factory.

 

personally, i wouldn't run that setup at all without rejetting. way too lean. these guys are dishing out some good advise for the right direction to go in. mikuni offers some killer setups that will really wake up your ride too

 

I can tell you from hands on it is not hard to do if you will just search ebay for Harley Davidson Carb Jet and pic out the kit that matches your bike it is from a guy from Texas call Sorgys he has his number on it give him a call and he will send you what you need for lest then $20.00 and you will think that you have a new bike.
I can tell you I try a kit call I thin it was Thunderslide and it was a waste of money unless you get it dyno but with the jet in the carb that he will send you put it in and drive off.

 

http://www.harley-performance.com/index.html

http://www.sportster.org/tech/carb/r...ng-bussy.shtml

http://www.keihin-us.com/tune2.htm

http://www.jetsrus.com/main_page.htm

http://www.jetsrus.com/FAQ_rejetting.htm

http://www.keihin-us.com/tune1.htm

http://www.jpcycles.com/Tech/Articles/jettingpipes.aspx

as you can see i have been there.

 

Yes TK353 I also did a lot of reading also and now doing it on EFI bikes

 

Good info here. Your gonna need the 48. You will know when she farts at the first stop light you come to. My plugs looked good to me with the 45 but it's hard to tell with unleaded gas. Spent a little money and did a dyno, and they put the bigger jet in. Cured