Hey all. Just joined the site was hoping for some possible insight to my problem. Just bought my first bike and learning to ride its a 93 sportser 883 with 26k on the dial. So my issue...with choke all the way in at idle the bike dies out. I can give it throttle and its fine but cant keep going with no throttle.

Ive done a little research but not sure where to go next. Im an automotive mechanic but never touched a bike before so im learning.

Checked basics, plugs good no intake leaks. Tried adjusting throttle/idle cables no difference. Drained bowl on carb, clean as a whistle. Carb cleaned everything and soaked jet still no difference. Only thing thats not stock on bike that i know of is open header exhaust (no baffles/mufflers) but again just bought bike but looks factory. With the open exhaust do i possibly need a bigger jet on carb? Also noticed the metal cap still in place over the A/F adjusting screw so it doesnt look like anybody has been in there...do i possibly need to adjust the mix?

Thanks for any insight!

 

1) When you cleaned the carburetor did you perform rebuild? If not I would buy a rebuild kit on EBay and just do it.

2) Search this site for carburetor mixture how-to. If the lead plug on the mixture screw is there, the mixture has not been touched.

3) Having owned several Sportsters, my personal opinion is they run like chit with open exhaust / no baffles. Many on this site will say I’m wrong and tell you different but that is my .02 cents.

4) With an exhaust change you may be able to get by with just a mixture adjustment. If you do re-jet I would go with a 45 on the slow and a 170 on the high (no bigger).

5) Set the mixture screw two full turns out and that should get you going. Then adjust 1/8 turns from there to fine tune.

Hope this helps … have fun.

 

Mine was having the same problem. It wanted to die at stop lights unless I gave it a little gas. Took it into my local Indy thinking he could just adjust my fuel mixture a little. turned out to be leaky intake manifold gaskets where the manifold connects to the heads. Not an expensive job, parts are like $26, the whole deal with a carb tune is costing me $100. Might be something you should check

 

Thanks for the replies.

run1fsr - I didn't do a carb rebuild yet...ran seafoam through, drained bowl and soaked jets. Everything seemed very clean but may look into rebuilding carb since I don't know the history of the bike. But the plug over the A/F mixture screw is still intact so maybe I will start there before replacing the jets or doing carb work. Clockwise for richer mixture and counter for lean? As for the open exhaust I figured that could be a problem...it was on the bike when I purchased (maybe not something I woulda done) but I must admit it sounds friggin awesome haha

Sikk50 - Sounds like something to definitely check. Excuse my lack of terminology as bikes are new to me but you're referring to the pipe behind the carb that connects the heads correct? I'm gonna be replacing the top end gaskets and seals as the bike is leaking all over so if the kit doesn't come with that I'll definitely change those out regardless for good measure while I'm in there..

 

pop that soft cover , adjust the low mixture , and idle screw.

carbs are carbs , whether on a lawnmower or a motorcycle..
aint nothing but a pinhole , and a pipe ...

 

Dave that's exactly what I'm talking about. There should be a gasket where each side of the tube connects to the heads. I couldn't find an intake leak, but the Indy found it in five minutes.

 

Not much holding the carb in place. A rebuild kit will provide a new O ring for the carb & manifold transition. Again, I would just pull the carb and rebuild it. You can expose the mixture screw with the carb sitting on your bench vs. the bike.

 

It's just like a car, the "pipe connecting the heads" is called the intake manifold. There are two gaskets on the engine side, and one for the carb side. Buy yourself a service manual and you'll have no trouble at all.

To remove that little mixture screw cover plug, use a small drill and a sheet metal screw. Drill out small hole, screw in screw, use pliers to pull out mixture screw plug. Easy peasy.

John

 

Little update...been messing around with the bike lately. In the process I've moved the carb out of the way a few times. Went to take the A/F cap off and noticed it was gone (later found it on the floor) so maybe somebody had been in there before and tried popping it back in. At any rate tried adjusting and to no avail...screw all the way in and tried it at different points up to 2.5 turns out (which is supposedly the max before considering a re jet?).

Took the carb apart...It's got a 40 jet (little one I'm guessing the slow) and a 160 jet (bigger one next to it I'm guessing high). And the long one attached to the bowl that sticks out and you can see when you remove air filter is a 70. Does that give any insight? I'm thinking maybe I'll try the intake manifold gaskets as well just to be sure

 

Okay, but I've owned several Sportsters with typically not a problem beyond the carb. Go with the jet sizes I noted earlier then 2 turns out on the mixture screw and it should fire up. From there adjust the idle as needed to get it running. Then adjust mixture and idle to fine tune. May take some time before you get it set right. I still mess with mine occasionally. Pulling the throttle cables from the carb can be a PITA but worth the trouble to get it on a bench and do the rebuild correctly.