Carb Question

[stinkbomb1020]

I'm a new member at this awesome site. I have done a lot of reading, and there is a ton of info. and good advice pertaining to everything KX related. I searched, but was unable to find out any info. pertaining to the specific problem that I'm having with my bike. Here goes the story thus far...
I just got a "91 KX500 a few days ago. I had to work on it, before I could ride it. Just some simple stuff, nothing major.
My Q is about the carb. When I finally get the bike cranked (my foot and leg is killing me!), it will not idle on it's own.
I have to turn and hold the throttle, just a little for it to stay running. This is most inconvenient when riding and having to slow down, as the engine will almost shut off completely, when the throttle is let loose. I do not enjoy having to kick the "!@#$" out of it, to get it started again!
Could someone tell me how to adjust the throttle and/or the carb to make it idle without having to turn and hold the throttle? I tried adjusting the long screw on the left side of the carb, while my wife kept the bike running. No matter how much I adjusted that screw, it made no difference in keeping the motor running on it's own. Is there another screw on the carb somewhere for adjusting the idle? Or, is the idle adjusted by the throttle cable?
One other thing I've noticed is that the bike seems to run too rich. Specks of oil droplets come out of the exhaust. It's almost like a black tar, I can see where some of it has built up and seeped from the muffler and pipe connection, and some from the exhaust header to pipe conection. I hope it's comming from the oil in the gas and not from the oil in the crank/tranny. The oil level in the case is at the half way make of the case viewer.
I took the spark plug out and it was oily. It takes me a lot of kicking, and it is hard to kick start the bike. It takes a while for me to finally get it running! I need to get some steel toe boots or something! These tennis shoes don't protect my foot so well!
I got a matienance/repair book ordered, but will not get it any time soon. I'm gonna drain the gas and try running the bike with a little less oil to gas ratio. Hopefully, this will eliminate the oil droplets and thw mess it is making. The oil mixture was 50 to 1, so that may be the culprit. Next time, I will mix it 40 to 1.
Any advice, links about the above would be greatly appreciated.
Thanks

[oldKXscrapper]

that sounds just like mine when i first got it, it turned out to be a mixture of knackerd reeds, a missing exhaust valve and blown crank seals, the hard to start part was down to the reeds, after replacing them it will go first time warm or cold aslong as i get enough force behind the kick.
as for fuel mix ive always ran every 2stroke at 25-1 with no problems.

[KXcam22]

sTINKBOMB,
  As a suggestion, run 50:1 with a good synthetic oil.  Before proceeding further, verify your carb jetting and set it exaclty like the jetting chart.  Then take it for a ride and post back.  Lots of problems can be fixed by leaning out the stock jetting. The chart is right on the money and a good place to start. hope this helps. Cam.

[BDI]

My 1990 kx500 didn't Idle and if you looked in the shop manual it said N/A because the bike was never intended to just sit and idle. Now the bike would sit and run for a bit before it would die you had to keep it alive with the occassional blip of the throttle. The screw on the side of the carb was nothing more then a throttle stop for the slide and was supposed to be screwed all the way in. I would definitely check the engines health as suggested above and also compression.You can't go wrong at40:1 with the oil. the bike should start and run good with a 55 pilot jet and the air screw turned out 1.5 to 2.0 turns. Infact your whole problem could be a pluged pilot jet does it run with the choke on and die when you turn the choke off? Have you tried cleaning the carb?

 P.S. 50:1 is less oil then 40:1,  50 parts gas to 1 part oil as opposed to 40 parts gas to 1 part oil.

[stinkbomb1020]

Thanks for all the advice guys, and yes, I was thinking wrong about how the oil/gas ratio works.
I think...I got it straight now, 40:1 is more oil mixture than 50:1. I used to know that stuff, but it's been at least 15 years since I had my old dirt bikes, a KX80 and then a KDX200.
I will try to do what KXcam22 suggested. I'm not that familiar with how to check the jetting and set it to the chart. I will search for a "how to" or info. about how to do it.
If and when I figure out how to do that, and If it doesn't help, than I'll take the carb off and clean it, and blow it out with compressed air.
As far as checking to see if there is an exhaust valve, am I right in asuming that it can be visually checked by removing the exhaust pipe from the header, and then looking in the exhaust port? If it is missing, how hard is it to replace? Is that part easy to find?
I don'rt even want to know how hard the crank seals will be to replace, if needed.
I was reading some post in this forum about a test that can be done for that, or was it for something else? Back to some more reading for me. I got the Clymer repair manual ordered, so that should help me understand more about the bike, and how to work on it. I will keep this thread updated as to what I have done to hopefully, get the bike running like it should.
Thanks again for all the advice.

[Johnniespeed]

  My KX 500 starts cold on the second kick and when warm starts on the first kick. My bike idles great,but I dont usually allow it to idle for more than a few seconds. Motocross boots have prevented many broken ankles and legs, if money is an issue get used ones, there are many for sale.
  You do not have to kick your bike until your leg hurts and you do not have to put up with a bike that does not idle.
   Until you get your bike sorted out, you could benefit from a "hotter" spark plug. It will foul less and that may allow you to figure out what is wrong.  "Hotter" has nothing to do with combustion temperature, all plugs fire at the same temperture. "Hotter" only refers to the plugs ability to self clean. NGK is numbered backwards so a   smaller number is "hotter"
  I clean my air filter once a week, they can be washed and re-oiled.
   This site will give you much more acurate advice than any Clymer manual.
  Keep trying, your bike can run great too.  John

[stinkbomb1020]

Thanks John, I hope so.