Drove the bike today to work and back after switching out the old spark plugs for new and did not notice a difference in performance. I have not had a chance to take the multimeter to it yet to see if the ignition cool is good or not. However I did notice the headlights dimming a bit when I first started it tonight. It seemed to coincide with the idle dropping out too. I will be checking the battery in the near future.

 

The lights dimming with the idle dropping is normal. Did you try a set of Plug wires? Also I would get a Tach to make sure you set your idle properly..

 

I have a set of new plug wires on the way. I don't have a proper tach but I do have a inductance tach that I plan to use whenever I get the time

 

Here's a bad one. This will definitely affect your idle and the overall performance.

 

I got a chance to mess around with the bike a couple times over the last two weeks, learned a thing or two.

Im pretty sure it's a carb issue. I say this because while the bike was running I pulled the rear spark plug cable off to see if there would be a difference in performance. There was a def drop in engine rpm and the throttle was markedly more sluggish. I also shocked the bujezus out of my hand. Safe to say that it's getting sufficient spark.

I have been messing with the mixture screw on the underside of the carb. I'm not sure how many turns out it is but I know it's richer than before by about 1 turn. It seems to run a little better this way, the idle is still pretty low at startup but it won't die on its own and the quality of the idle seems slightly better, tho not much faster.

i still plan to check the ignition sensor and ignition coil but it seems to me that it's carb related. In which case I plan to rebuild it this winter.

 

I have a CV on mine and mine will idle slow and want to die out when cold. Dont let it run on that really slow idle. If its like mine when cold its running at 500 RPMs or so and thats bad for the bottom end. It really wont idle normal untill warmed up. Run that screw
in all the way untill lightly seated and back it out 2 and a half turns and start from there

 

I've got a 94 road king too.

I'd give a try, spraying down your intake joints with carb cleaner and see if the idle raises.

A dead slow idle can be an air leak at the manifold to head. Might also explain your white plug compared to the other if she isn't burning oil...

While you are at it, feel around the exhaust for any leaks when you have her started up. Exhaust leaks can make for a rougher idle if they are big enough. Sometimes they swell up enough when hot to smooth out.

Its worth replacing your plug wires too, if they are original... or even just old. They make a big difference in how they run at low rpm.

Another thing that can be weird, is if the accelerator pump is shot they'll idle weird.

 

Ok everybody, it took a while (2 kids under 3 w/ one on the way, moving, off shift work schedule opposed to spouse's and general broke-ness leave approx 1 hr of free time a week), but the problem(s) I was experiencing have been virtually eliminated.

I had planned to rebuild/upgrade the carb using one of the kits available through the CV performance website along w/ replacing the fuel inlet w/ a brass one, replace fuel line w/ 5/16" and choke cable and finally got around to purchasing them. I removed the carburetor to thoroughly clean it and discovered that the jets were 42 slow and 180 main. I think stock is 42/170, so I figured this much of a difference between slow and main jets may explain some of the rough idle and slow speed issues. My dad was the previous owner of the bike and had carb work done in the last four years or so, i'm guessing that's where the 180 jet came from but why they did not bump the slow jet is beyond me. The accelerator pump was also rather nasty. After cleaning it, replacing most of the rubber/replaceable parts and rejetting to 45/180 I put it back on the bike. It was then that I believe I found the other missing piece of the puzzle.

The bike has had a Kuryakyn hypercharger for most of its life that utilizes a vacuum hose connected to the VOES/carb vacuum lines which controls the open/shut action of the butterfly valves which regulates air flow into the air cleaner. Also, it has an aftermarket petcock valve that does not rely upon the VOES vacuum line, unlike the stock version. Thus the bike ended up with two T bars worth of vacuum lines between the carb and VOES switch but with a vacant unplugged hose that used to go to the old stock petcock. The VOES was leaking and essentially not being used at all this entire time. Since it was such a mess I just decided to run a single vacuum line between the carb and VOES and let the hypercharger butterfly valves remain open.

This made a world of difference. The bike started right up and after some adjustments to the idle and mix screws it was running MUCH better than before. I think I have to do some more small adjustments w/ the mix screw as there was a hint of hesitation taking off from the first stop I came to but none after. In a word, SMOOTH!

The bike starts right up, warms up much faster than before, idle and low speeds are very consistent and stable and with some minor adjustments w/ the mix screw I believe I can eliminate the hesitation from before. Even w/out further mix screw adjustments however the hesitation was minute compared to how it was and possibly caused by being in storage for almost 3 months straight.

Anyways, I just wanted to let you all know that I did not forget about the forum and give a long overdue update!

 

Glad to hear you got it all figured out.

I personally think those Hyperchargers are crap... Worst type of Air cleaner I ever seen...... I would get rid of it......I believe they are nothing but a restriction....