Carb question
 

I've got a 2005 883 with a Ness Big Sucker I. Putting drags on soon, so I know I'll have to rejet. My 2 questions are: how do you know what size jets to buy? And, should I just take it to a shop?

I've rebuilt dirty cv carbs before, I just don't understand the process of knowing which size to get/install.

Everything you need to know is here:
http://xlforum.net/vbportal/forums/s...d.php?t=642408

another good one:
http://cv-performance.com/harley_mixture_screw_tuning

Simple answer, go one size up on the low speed jet and adjust the mixture screw - if the carb hasn't been touched before, you'll have to pull the soft metal plug covering it; that's easy, just drill a small hole in it (not all the way!) and screw in a self tapping screw which you can grab to pull it out. It'll get you in the ball park and run nice. You can do this with the carb on the bike, though it helps to get it loose enough to tilt it 90 degrees so the bottom is pointing sideways and you can reach things easier. I've even done this with stock pipes and it ran better.

You can fine tune it drilling a hole in the slide and messing with the needle, but most folks would notice little difference, if any. Leave the main jet alone unless you like running 5000 rpm a lot; at most highway speeds, the low speed jet still makes the difference.

You can use the search feature to find a lot of sportster carb tuning threads on this forum, and there are youtube videos, too.

You have two choices IMHO: 1, learn to become an expert, or live in hope that you get it right; 2, use a competent local tuning shop who has already learned! This is all a bit tongue-in-cheek, but in my modest experience tuning a carb falls into the dark arts, which I for one have never mastered. Fortunately I found a man who is ace!

Thanks for the info, guys. I really appreciate it. I'll read up on those XLForum posts. I'm not 100% sure I want to do it myself... The main reason I want to do it myself is for a) the experience, and b) saving $$$ by not taking it to a shop.

There are great shops in Pensacola, but the hourly is spendy wherever you go... That said, I appreciate the info, and will post back with my findings/decision.

Most of us use a 45 size pilot jet, with main jet sizes 170-180 or so. I bumped my pilot to a 45 from the stock 42, and may fiddle with a 48 size eventually, although plugs are looking really good so far. A member over on xlf swears a 48 pilot is the way to go. IDK. Anyone else run a 48 pilot jet on a stage 1 883???

Changing the jets is super easy. Just use a long hollow ground tip screwdriver for the pilot jet, not a standard wedge screwdriver. The carb bowl screwheads are JIS type, not exactly Phillips heads, so be careful removing if you use a Phillips screwdrive. I also changed my intake manifold seals when I recently re-jetted my carb. Very easy and highly recommended with a 12 year old bike like yours, mine were 25 years old!!. There is a tutorial over on xlf, but it's pretty simple to figure out. Three seals, a stubby allen wrench, some red grease, done.

John

I'd think you wouldn't run any larger pilot jet than you needed to run smooth, bigger would just waste gas, run rich. When you're getting on it with stock or higher stages, you're getting into the main jet anyway. One size up pilot jet, and tweak the needle with shims if you really wanted to get it in the sweet spot for that transition from pilot jet to main. Also, with a size 48, your mixture screw might be way off from the normal turns out; that would be a good indication the jet is too big.

Agreed. I'm glad I tossed the issue out there. I read of no posts using more than a 45 pilot, especially on an 883.

John