I have a 99 FLSTC with a Mikuni carb. The problem im having is white smoke comes out of my exhaust only after the bike is warm. It starts up just fine and sounds good. No smoke when I first start it up in the morning. But after it warms up, its a different story. It smokes when i stop and i,ve been told that it smokes when im riding as well. I,ve changed the spark plugs as well as the wires. The old spark plugs were black and smelled like gas. Im new to Harleys and would much appreciate any help I can get.

 

White smoke? If its a little blueish thats oil, a little greyish thats fuel. Might be over fueling it if you smell gas and there black that seems to be over fueling. Miht need to change some jets in the carb to get it right or you may need to rebuild the carb. I'm not up to speed on Mikuni carbs so someone else will offer some better advise.

Welcome to EVO's and the forum.

 

If the old plugs were black and smells like gas you are running too rich. Adjust your fuel/air mixture screw.

 

Make sure you are not running the engine with the choke/enrichener on.

 

First make sure the enrichner cable is fully seated so that you know it is closing all the way in the carb. Sometimes the elbow comes out of the carb.

 

Mountainkowboy: I think your right when you say that it might be greyish. One thing I forgot to mention is that the smoke burns my eyes when im at a light. Someone else told me that I might have to change the jets to a smaller one. Dont know if thats true or not.

 

Im new when it comes to Harleys but the choke is on the left side right? If so then it is all the way in. I have a short cable with a twist **** at the end of it. Its coming from the carb. Im told that its to adjust my idle. could that have anything to do with my bike running rich?

 

Could be.

 

Sounds like you have a Mikuni. The short cable on the right side is idle speed adjustment, the **** on the left side is the enrichner. It is fairly common to find the elbow from the enrichner either not fully seated or pulled out of the carb. This causes the enrichner to stay on even when the **** is pushed all the way in. Unlike most other carbs, the mikuni enrichner works as long as you are at idle. As soon as you give it some throttle the internal circuits turn it off, so it could be staying on and wouldn't be noticed.
If you find that is not the problem then look on the carb, just inside of the air cleaner on the side towards the rear and you will find a straight slot adjustment screw. Mikuni idle air adjustment screw changes the mixture quite a bit so if you turn it in a little it will lean out the mixture. If adjusting the idle air mixture doesn't fix it then a jet change/ float level check is in order. You can go on line and down load an owners manual for the mikuni 42 carb and all the information you need will be in there in fairly easy to understand language. Hope this helps.