Carburetor gasket.

[pitbullsuperglide]

Thanks for the advice. Lots of great advice here. I appreciate everybody's input. Thanks again.

 

[dolt]

I got the next size up main jet too. Should I hold off on that one until I get the low speed sorted? My plan is to install the new pilot jet, turn the mixture screw back to about 1 3/4 turns and start from there.

First things first; address the low speed circuit first. While the motor is cold, Install the 45 pilot (slow) jet. While you have the bowl off, take the A/F screw all the way out and check the washer, spring and o-ring for correct assembly. I would suggest a new o-ring, over time, they flatten out and I have seen them turn sideways in the bore. Blow out the A/F port to make sure it is clear and reinstall the A/F screw assembly; set at 2.5 turns out.

Start the bike using the enrichener for about 30-60 seconds, then push the enrichener all the way in and use the throttle, if necessary to idle the bike for a few minutes. Take a couple of spins around the block to get the bike up to operating temperature; makes carb tuning a bit more of a challenge; easy to burn knuckles but, operating temp is necessary. Quick warm up and a couple of spins around the block will do it. Once up to operating temps, set the idle rpms between 900-1000.

Turn the A/F adjuster all the way in. The motor should stumble and possibly die when the adjuster is all the way in. However, if there is no change, pilot (slow) jet is too big. Now slowly back the A/F adjuster back out listening to the exhaust and watching the motor vibration. The A/F screw should end up between 2-3 turns out to produce an even exhaust note and minimize the motor vibration. You may need to turn the screw in and back out several time trying to find the sweet spot. Believe me when I tell you that even 1/8 of a turn will make a difference.

Once you have this right, the motor should respond without hesitation to a quick blip of the throttle, smooth idle, no backfire, no cough, just a quick throttle response. Once you have this sorted out, you can move on to tuning the mid range (needle) and WOT (main). Once you get the slow speed issues sorted out, fill the tank, take a 100 mile ride trying to maintain between 65-70mph. Fill the tank and check mileage; pull the plugs and take a look. You can use the mileage to adjust the needle; if mileage sucks, drop the needle; if mileage is too good to be true, raise the needle.

Once you are happy with the needle setting. You can get a handful of new plugs and tune WOT with plug cuts.

Keep us posted on results.

You can also check out the Nightrider section on the CV carb.

http://www.nightrider.com/biketech/hd_cv_mods.htm

 

[TQuentin1]

I love the Keihin CV carbs. So easy to work with.

You may wish to get the aftermarket Air/Fuel adjustment jet screw as shown in the link below (you can probably beat this price!). Makes adjusting that a lot easier than trying to find the slot in the OEM adjuster with a small flat blade screw driver while the engine is bouncing all around!!

http://www.edgextremesports.com/idl...jGnhvLAPIV_9PLmJs3lxDhfcdPQsGhkwaAmbjEALw_wcB

Cheers,

TQ

 

[NCBILL]

It was raining here today in Eastern NC, so I figured I'd go ahead and take MY carb apart on my 06 Sportster, just to see what size jets were in my Keiln CV set-up, and, to go ahead and give it a good cleaning while I had her apart. Found out my stock slow-jet is a #42 and main jet is a #175. My carb does in fact have the accelerator pump, but I'm wondering if it would hurt to try the #45 vs: the stock #42 slow-jet? It seems at times to be starving for fuel at low speeds, and sometimes misses a beat, hiccups at slow speeds. New plugs installed a few weeks ago didn't seem to help the problem. I'm just thinking the stock jet is too small. Ya'll reckon' the upgrade to a #45 will help? Thanks.

 

[tourbox]

Can't hurt it any. It will warm up faster from cold start. If it is too rich after that you can go back down on the main to a 170
tourbox

 

[NCBILL]

Thanks Tourbox. Always some good pointers & info here on this site, and good folks willing to share that info and experience.

 

[fin_676]

The 45 slow jet will help it start easier and warm up quicker and all its extra capacity at all throttle openings so it may require slightly less main jet as tourbox has said
Remember only change 1 thing at a time and see what happenes
A carburettor is always a compromise and can not deliver ideal fuel air mix at all throttle openings, you just need to find the best settings for you and your bike by trial and error one wee bit at a time

Brian

 

[dolt]

Ya'll reckon' the upgrade to a #45 will help? Thanks.

Good advice from TQ on the aftermarket A/F screw, might save a burned knuckle or two. I would put the cleaned up carb back on the bike as is and get the motor up to operating temp, screw the A/F adjuster in all the way with the 42 slow to see how the motor reacts. Could be that all that is needed is another 1/2 turn out to eliminate the hiccup; could have been some crud causing the hiccup as well. Stock with a clean carb is the best baseline to start when tuning a carb.

Don't disagree with Tourbox; the 45 won't hurt anything but may not be needed. JMHO.

 

[pitbullsuperglide]

Ok, got the jet installed, seems much better. Started off at 1 3/4 turns on the a/f screw, took it for a ride around the block a few times, got it nice and warm. Played with the a/f screw a little, and it seems to be happiest at around 1 3/4, so I left it there. Went for a short ride, no pops at the carb or exhaust.
Thanks everyone for the help and advice, it is really appreciated!
I haven't put the bigger main jet in yet, I think I'm going to just leave it as it is for now.

 

[NCBILL]

I forgot to mention, the HD Part# for the #45 slow-jet is: 27170-89.