I'm getting ready to install an aftermarket free flow air cleaner and I'm looking for info on rejetting the carb.

My bike is an 04 1200C with Screaming Eagle pipes and currently a stock AC. With the new AC I want to rejet the carb so the bike won't run too lean. I have the service manual for the removal and disassembly so that's not a problem.

I just read an article by Joe Minton with American Iron Magazine (May 2011) "By the Numbers, Tuning a Stock CV Carb" and have some questions maybe some of you can comment on.

In the article he states "Personally, I've found that a 42 slow jet was the best size for every Keihn I've tuned and cannot recall ever using any other". My 04 1200 comes with the 42 stock so I don't plan on changing it. Comments?

Another comment Minton makes in the article is "The stock main jet is usually correct for a harley fitted with a free flowing air cleaner and exhaust system". So essentially he says to leave the main jet alone too.

In the end the only adjustments Minton recommends is changing the needle jet (in the top of the carb) and adjusting the idle mixture screw (after drilling out the cap). Minton says the "magic needle" was developed for the early 1200 Sportster, part number 27094-88, and is still sold by Harley.

Have any of you done this? Did it work? Is this what the dealer would do? I've read that you should stay out of the top of the carb but it sounds simple.

Give me some feedback please.

 

Haven't read Minton's article but my '05 XL1200R needed a 48 Slow Jet and a 185 main to run properly (without "farts" or hesitation) when I swapped the stock A/C for the S&S A/C and went to SE II (original) slip-ons with BCT baffles. My bike runs amazingly well with these combinations.

 

The Harley Performance website is the best thing going for tuning a CV carb.

 

I just re-jetted my bike with the help of an awsome article in "american iron magazine". Basically it goes on to explain that the best results come from replacing the needle & slow jet. In most cases the main jet is the right size. For even more adjustability there is an air mixture screw that can be adjusted once the aluminum plug is drilled out.

 

I'm quoting my own msg to answer yes I did these exact adjustments and it was easy! My bike has never run better! Alittle tip; when drill the plug use a 9/64" bit seemed to be the right size to work the plug out. And I went ahead and used the 42 slow jet seems to be the right one for me! This has been the best mod I have done to my bike yet!

 

Yeah I've done a little reading there, pretty good site.

 

I think your referring to the same article.

Thanks for the tip.

 

Manual says my main is 170/195, so I guess I'm some where in between those numbers, not sure.

It sounds like the Minton procedure is a little simpler since I only have to change the one needle.

 

I have a 46/180 in mine, didn't have to touch the screw. Bike runs great!

 

I stopped in at the dealer and was told they change the slow jet to a 45 and pretty much leave everthing else alone. What they do conflicts with the mag article but I know that doesn't mean it's wrong.

I've read some other threads on jetting and it seems everyone has something different. Guess I'll just have to play around with it.

Thanks for the replies.