That's a rich condition. Check the air cleaner, then if it's clean look at the carb. There is an off chance that the spark is weak and not burning all the mixture. Check these out and get back to us. Also what carb are you running??

 

i am running standard carb . spark does seem very weak but i changed coil, coil lead ignition batterry etc ?

 

Bobhog, sorry about not getting back to you, away on vac. So it appears that my brothers here are trying to make sense of your problem. We need as much info from you as possible. What make carb???
MP

 

I'll throw out two suggestions.
1. I know some people like the Autolite plugs, but I found the NGK to be far better, especially the iridium ones. They fire much better and don't gum up as much in my 90 FLHTCU.
2. It sounds like it is simply over-jetted. Have you tried dropping the main jet a size?

Finally, you might run some Seafoam through the tank - I like that stuff and it does a good job of cleaning fuel systems.

 

Okay, I went back and disected/decoded your OP.

If the bike is totally stock (carb, cam, intake, exhaust). It is highly likely that you have a over-rich mixture. This can be caused by a number of issues with the CV carb.

Definitely check the enrichner. If it's not 'pushed all the way in' you will get the rich condition. What RPM is the bike idling at when warmed up?

Check the float needle. It could be 'gummed' up and causing the bowl to overfill.

Check the float level.