So I gathered all the info I could on tuning the carb but one thing is still unclear, do I use 1 or 2 .035 m4 washers? I have heard you shim it .030-.035 but other people are saying use 2 of these washers. this is for an 05 883 btw thanks in advance.

 

I went one at a time on my 2006 flht , to kinda "sneak up" to the final setting.
This way I could check for the feel of the change.
If you have a free flowing set of mufflers and air cleaner too , 2 would be safe anyway.
I eventually ordered the 27094-88 needle from the dealer and it worked a bit better.
I think at the time it was around $9.00 for the needle.
Mick

 

Keep in mind what works for others may not work for your setup. The throttle jet needle comes into play within the 1/4 and 3/4 throttle position. It does nothing in the idle position as well as in full throttle. If you are running lean and want to add some more fuel to richen it up you will either lower the clip and/or add washers (raising the needle) for more fuel. If you want to lean it out some, you do the opposite. Testing is the only way you will find what is best for you.

 

It depends on your situation and needle shape. Shimming the needle will richen the entire range the needle is affecting. I would start with only one shim. .035 is a pretty decent shim. I typically use .020" nylon washers when I'm shimming carb needles.

Also, it doesn't matter on a Harley with one carb, but if you are doing multi carb bikes make sure to verify washer thickness. I've seen shim washers that are .004" or more difference between each other. I don't want to put two different shims in the carbs!

 

If you're running the stock CV carb with stock needle use 2 #4 brass washers on the needle, I've had the M4 washers stick in the spring seat cage due to their diameter causing the needle to float. The #4 washers are slightly larger than the head of the needle and do not cause any binding of the needle in the cage. You can find #4 brass washers at most hardware stores...

If you're interested in playing around a bit try one washer then two washers on the needle and see how you like the difference, I settled on using 2 early on and with my carbed Sportsters, BT Evo's and Twin Cams that's the setup I used

Edited to add: Now I'm curious, if you can post up your bike's setup and your current carb settings, I love working with carbs and with only a FI '13 Wide Glide in the garage right now I have to live vicariously through those lucky enough to still be kickin' it old school

 

45 idle jet stock main atm. Bout to install rebuild kit due to leaky accelerater pump diaphram. Just replaced intake manifold seals. Removed stock exhaust baffles, trying to decide if I should save up for a legit air cleaner or just get a stock k\n drop in (broke atm). Also should I just opt for the upgraded needle from cvperformance or shim the stock 1. Trying to see how good I can get it to run for as little money as possible. Bike has 25k on it but seems to run pretty good. I just like tinkering with my stuff. Thanks again peeps

 

Cool Carbs are fun to tinker with, they are as much art as science, so many subtle changes can be done to get a sweet running machine. The HD 27094-88 needle does work well but if you're shimming the stock needle you most likely won't notice any benefit from changing to it and if it were me, I'd shim the stock needle, HD did get it right with the taper of the stock CV needle, just needs a shim or two; save the cash there and try one or two shims instead of going to the aftermarket CV Performance needle.

Do you know where the air mixture screw is set? If you're at 1 1/2 turns or in that neighborhood with the 45 you might want to consider the 42 pilot but with baffles out of the exhaust you might be on the money with the 45, hard to say without actually seeing your bike but the idle will tell you, if you blip the throttle with the bike completely warmed up and the idle drops slightly then settles, too rich on the pilot, it when you blip it and the idle moves a bit high then settles, it can indicate your pilot may be too lean. Sweet spot on those '04-'06 883's was around 2 1/3 to 2 1/2 turns on the air mixture screw but if you're over-jetted on the pilot you end up needing to dial back the air mixture screw past the sweet spot.

Before I did the 1250 conversion my '06, with Cycle Shack slip-on's and an open foam element A/C I ran the stock jets with the needle shimmed and 2 1/2 turns on the air mixture screw, after the 1250 upgrade I went to a 45 pilot jet, kept the stock main and the 2 needle shims and the air screw ended up at 2 1/3 turns out, she ran like a beast, great color on the plugs... Never should have sold her.

You could consider the K&N as an option for your A/C, the engine is most likely getting more air that it knows what to do with at it's current build state anyway so save your coins and buy a nice looker when you can. I'm of the opinion that the exhaust plays more of a role than the A/C when it comes to tuning, even the stock A/C gives the engine enough air until you start doing engine upgrades but change out the exhaust with a stock engine and stock A/C and that's where the tuning fun begins...

 

Alright, got parts today, rebuild went smooth except the new float valve was much shorter than stock so i didn't mess with that, installed the rest of the parts and a 45 idle jet, went for broke and added 2 shims to needle and the test ride went like ****, no matter how much I adjusted the mixture the bike just ran like a turd. So i took out the shims and set mix screw to 2.5 turns out and it ran like it should.

Now I got some questions, i was thinking with the larger idle jet I should have to turn the mix screw in a little to even things out but it seems to like the exact same mix as the 42 jet. Also i'm gonna take your advice and grab the #4 brass washers and just throw 1 in for now, the ones i have now have an outside diameter so much larger than the needle head (maybe that was my problem).
I seem to have trouble with fine tuning, do you have any tips? I just can't seem to get the idle drop method to work for me, I guess my best bet would be doing that with a tach? Or getting some new plugs, My next upgrade is def going to be an air cleaner,if for no other reason to try and remedy the oil collecting in the air filter.
thank again for all your advice

 

If you are considering a plug change, I have had luck with the NGK Iridium plugs on the sportsters. Noticed quicker starts and a better idle. If I remember correctly after an iridium install on an 05 that I did for a friend, the only thing I had to do was richen it up a little because it went a little to the lean side. That bike was basically stock with modified baffles. Others I left the same.

 

Aren't carbs fun?

I honestly would not do any further tuning until you try the #4 brass washers so you'll know what effect the shims have, if you did install the M4's and they hung in the cage that would explain why the bike went to crap and was better with them out, the needle got hung and couldn't drop, no matter how much you adjust the air mixture at that point it's hopeless. You'll want to make one change at a time, wholesale carb changes are maddening since you'll never know what caused what

Running a 45 pilot I'd be surprised if you don't have to turn in the air mixture screw just a bit, see if your local HD dealer has a 44 pilot available so you can compare the different sized jets and see what works the best for your current setup, sometimes it takes days of riding on each before you really notice their differences. Some bikes like a 42, some a 44, some like yours might want a 45 right out of the box. I noticed on that 'other' Sportster forum it was pretty common to just throw fuel at the bike, so many people just ran them pig rich but you can get a great tune with excellent performance and some decent MPG too. Doing some riding on each jet you'll start to get a feel of where the mileage is, if it's abnormally low or freaky high you change jets accordingly.

Doing the fine tuning of the air mixture using the idle method is a bit tricky, a tach does help doing it, you can see the effect instead of trying to listen for it. Sometimes you'll think you're right on, take the bike for a nice ride and when you get back and blip the throttle in the driveway the idle hangs or drops slightly before stabilizing, nature of the beast and then that's the fine-fine tuning on the air mixture

When it comes to the A/C and the crankcase breathers I've always vented to atmosphere, the idea of dumping hot oily gas back into the intake is not what the engine wants at all, only the EPA. I've had great success with the horseshoe style breathers with the CV carbs, I'm currently running the DK Custom breather bolts on my '13 Wide Glide and love the clean look they give. If you are going to replace the A/C check out DK Custom, lots of well made options for the Sporty and designed to vent the gasses instead of dumping them back into the A/C.

I found an old image of my last Sportster, this was taken the day I did the 1250 conversion, you can see the horseshoe breather. I did quite a bit more to her but foolish me didn't back up my images and I lost a ton of them in a Photobucket 'mishap'... doh