low speed carb re-jet

[SpringerSteve98]

Spray some WD-40 around the intake manifold while its idling. They could have jarred the intake a bit or not made sure it was sealed properly when they took off or replaced the carb. If it idles up when you spray it or changes idle at all its likely leaking. That would cause rough idle, and hesitation/coughing when taking off idle, and loss of power.
If thats not it, see if you can adjust it out with the mixture screw.. If you can seat the mixture screw and it doesn't kill the bike, the pilot jet is too rich. and you'd need to step it down to a 46 or so. (if there is indeed a 48 in it)

Oh, almost forgot to add. Be sure to count your turns when you start to close the mixture screw. Hard starting warm is usually a rich condition, turning the mixture screw clockwise will lean it up some. Checking the intake manifold for leaks, and playing with your mixture screw shouldn't void your factory warranty. If it is under warranty and you can close your mixture screw all the way without it starting to stumble or dying i would ask them to put in a pilot jet that is a size smaller.

 

[Peso Joe]

I had exactly the same problem, and it was traced back to two things.

1. The 48 Jet is too big. In fact I bet you will find that the mixture is ALL THE WAY IN and the bike will still run. I now have a 46 installed and the Mixture is out 2.5 turns. Also a 190 is the stock main jet for that year. A 195 is what is installed in mine now as well. The 46 is NOT a comon item and can be purchaed at JPcycles.com that is probably why they went with the bigger jet since 48 is the next size up from 45 in most kits.

2. And this was the kicker. before the 46/195 was installed we also found that the vacuum line from the Fuel tank petcock was slightly old and brittle. it was REPLACED and the hard starts disappeared. After the proper jets were put in and the needle height set proper all is right with the bike. (Got rid of the adjustable needle and went with the CV Performance needle which mimicks the Old Sportster needles.

Lastly, since the "techs" were in the carb, they may have installed the needle jet holder upside down. FAT SIDE goes UP. if you remove the aircleaner and run the bike you will see the shoulder sticking up around the needle. Run the bike at ible, if it is dribbling fuel then it is UPSIDE DOWN. it also sets higher around the needle when properly installed.

Good luck.

 

[robertnj63]

Thaanks everybody. The bike seems to be running pretty good with that 48 jet in it. I may ride it for this coming week before calling the dealer. Im curious, does the 48 jet have any influence on the performance of the bike at higher speeds. I dont know if its just my mind, but i find myself at full throttle more often. I dont have a service manual and do not find myself confident enough to play with the jets in the carb, so of course i am releuctant in telling the dealer he put a too large jet in, so having the printout from this thread will be so helpful. I wish we had a "glider" in every state!!!LOL I may get the 46 jet from jpcycles so i have it when i bring it back to the dealer. I would really like to know though if the 48 jet impedes performance.

 

[glider]

The #48 jet is a bit rich and will loose a bit of the crispness in the throttle. The 46 would be a better choice.

 

[SpringerSteve98]

Thaanks everybody. The bike seems to be running pretty good with that 48 jet in it. I may ride it for this coming week before calling the dealer. Im curious, does the 48 jet have any influence on the performance of the bike at higher speeds. I dont know if its just my mind, but i find myself at full throttle more often. I dont have a service manual and do not find myself confident enough to play with the jets in the carb, so of course i am releuctant in telling the dealer he put a too large jet in, so having the printout from this thread will be so helpful. I wish we had a "glider" in every state!!!LOL I may get the 46 jet from jpcycles so i have it when i bring it back to the dealer. I would really like to know though if the 48 jet impedes performance.

At higher speeds it will effect roll on/roll off... But if you're having to hammer your throttle to get up a hill i wouldn't think the pilot jet would have anything to do with it. I recently went through my carb 6 times while having similar symptoms you seem to be explaining. Turns out my intake was leaking, which made it nearly impossible to read plugs or jet the carb properly. Fixed the intake leak, took one look at my plugs, and knew just what to do. Loss of power doesn't nessecerily mean your jets are wrong though. If you have stock exhaust, and haven't had your carb rejetted. The stock jets should be fairly close. I'd say check other things, but i'd pull your front plug to have a look anyway, they tell a story. Check for white ash on the topmost part, or around the top of the insulator, that would indicate a lean condition... If there is a ton of blackness its likely to rich. Check the front plug after getting on it a few miles on the highway, _and_ just after putting around in town for 10-20 mins (under 1/4 throttle, and easy take off's) The highway read will be more of your main jet, and the putting around will tell you a story about your pilot jet.

Oh, and if you see white plugs, and ash like stuff on the tip of your plug... Don't be getting on it much, the white ash stuff you're seeing is aluminum burning.

 

[robertnj63]

Hey "glider", what state are you from? I would love to have an expert like yourself to work on my bike. Just wish i could find someone with even half your talent here in New Jersey.

 

[glider]

Hey "glider", what state are you from? I would love to have an expert like yourself to work on my bike. Just wish i could find someone with even half your talent here in New Jersey.

I'm from the state of confusion but I don't do much work anymore if I can help it. :s

 

[mrriehl]

I find this all very interesting. I have an '05 FXD I bought 1 year ago. When I test rode it (with only 9,600 miles on it) it ran like poop! I knew it was probably carb related and bought it anyway. Since then I stripped down the carb (with lots of help from this site) and cleaned everything and put it back together. It still ran poorly. I accessed the air/fuel screw and made some minor adj. Not much improvement. I can wrench OK on most things so I have the confidence. What I learned this morning from this site has shed totally new light on my problem. I have heard many times the CV Carb is good stuff and my enthusiasm for tackling this task once more has been renewed.
Thanks to EVERYONE!! YER AWESOME!!!