Update again,

after I have rebuild the carb completely (new diaphragm, changed slow jet from 45 to 42, changed jet needle) changed spark plugs with SE spark plugs, changed plug wires with SE plug wires, the bike is still running bad. Also twisting idle mixture screw has no or very little effects on idle speed, but when it is opened 2,5 turns more black smoke is coming out.

One day it starts perfectly, the other, no increase in revs on choke, dies without choke or throttle, a lot of black smoke on front cylinder, fuel consumption around 33mpg, black plugs... On the other hand in transition and high speed the bike is running great, but with poor fuel economy.

I am pretty running out of options, and in my country, unfortunately the support is pretty bad (diagnostic is very poor).

Currently Im considering if some of electronic components are faulty, even though I get no codes or errors. I am suspecting MAP sensor might be giving false data??

Could MAP sensor or any other electronic component cause such symptoms?
Does anybody knows what is HD part number for MAP sensor for sportster 883 custom 2005, so I could order it? I could not find it on the web.

PS. with all this Ive mastered carb dis assembly/assembly

 

On my 88 it did this so i stopped using the enrichener unless it is below 40. I turn the igntion on and crank the throttle three times and then hit the start button and have had not issues. Whne I do use the enrichener I only use it till the bike fires then i turn it off no longer than 10 seconds. Also check your coil you could have a faulty coil. You have a problem with on e side of the coil where it is not delivering the right amount of spark when cold. I had the dual fire system and my bike was always a pain to start until a went to the Crank single fire kit. Boy what a difeance that made.

 

Thanks for the suggestion Pappassportster.
What is the easiest way to check if the ignition coil is malfunctioning?

Today I just swapped front plug wire to back cylinder and back wire to front cylinder. The engine didn't started, like there was no spark. When I connected wires front to front and back wire to back spark it started normally. Is this normal or it means that there is some problem with coil?

 

I was having similar problems. That is what led me to this forum. My local indy jetted my carb for me. In the process messed with the air screw. He assured me that it was just right. Well, it didn't run that great. He had jetted it to much. So, I went and bought some new jets from him and put them in myself. Still run sluggish, turning my plugs black. Finally someone told me to check the air screw. Screw it all the way in and count the number of turns. My indy kept insisting on two turns. He even said two was a lot. I called HD and they said three and a half. So, i thought, what the hell. Three and a half it is! It fixed my problem. I purchased the SE jet kit and 3 1/2 turns later, my bike runs great. Plugs look good. So, if you havent checked the air screw, you might want to. Just my experience.

 

As far as the plug wires yes that is normal because your ignition is firing the cylinder that needs to be fired if you switch it your timing is off. I would also check out what Razorback said if you have not already fixed the problem. There is really no easy way to check your coil. But if you are firing clean on one cylinder and not on the other and your compression is good you only have one other option and that is spark. cause I think if you had a air mixture issue it owuld be on both cylinders but I may be wrong on that. Again I would check out what razorback said cause that sounds like an easy low cost fix then if that doesnt work I would replace the coil.

 

After really exhausting hunt, the search is (I hope ) finally over!

The problem was with stupid petcock, the diaphragm was faulty and it was leaking fuel through vacuum hose straight into the carb!!! Found out this by playing with petcock switch and discovered when I put the switch somewhere in the middle position between on and of (or res and off) the bike is running perfectly.

Ive installed petcock without vacuum and the bike is running perfect. Had few issues with intake/vacuum leak but finally resolved it today. Now waiting for Pingel to arrive!!!

So, the conclusion is, for all those who has issues with unexplained running rich condition like I did: if everything in the carb is good check the vacuum petcock!!!

Again, thanks for the support.

 

Is the Pingel you ordered vacuum? I guess if it's not, you have to turn the fuel off every time you stop. Is that the case? Are Pingels worth the money? What makes them better. I've never heard.

 

No, I ordered pingel petcock without vacuum, hex model 6000 series.

http://www.pingelonline.com/powerflo.htm ,

There is also pingel with vacuum but it is more expensive, but I opted for model without vacuum based on other people experiences.

Yep, without vacuum you have to turn off fuel every time when the engine is not running.

What makes them better, specially than stock petcock, is that they are quality built and more reliable. This is based on reading on other people experience, again.