So I bought a 1994 sportster 883. It has 20,600 miles. The carb on it is original. It wont run right unless i keep the choke out. I was told by the previous owner that the people I ended up taking it to for new tires, were the ones who cleaned the carb back in April. The prior owner thinks they didnt readjust the carb after the work. That seems pretty shady if they did, so its not easy to believe because this shop has a good rep. On top of all of this the gas that was in it was VERY old. Some of it might have even been as old as two years. If it was 'cleaned' back in April, wouldnt they have drained out the fuel if the carb looked dirty? These are just 'want to know' questions. My diagnostic question is once I pull the carb, lines, petcock, change fuel filter, attempt to flush the tank (whats the best way to do this BTW), how will I know if the carb needs rebuilding or replacement. And what would dictate me needing to replace instead of rebuilding. Rebuilt carbs are sold all the time.

 

carbs can almost always be rebuilt. Primary reason peope buy rebuilt replacement carbs is because for some reason they are afraid of tearing into a carb. If it were me, i would flush out the tank, add new fuel and try running a pretty strong solution of seafoam or carb cleaner in the gas, then make appropriate adjustments (could be that the idle speed is just not set right. If taht doesnt work, tear back into the carb.

 

Very, very unlikely it needs replaced unless someone has physically damaged the body itself.

Rebuilt kits are usually just new gaskets, float valve, mixture screw, and jets. The rubber wears out and can stop sealing right, and the old gas evaporates and leaves a varnish that plugs the ports. If left long enough it will start to resemble Jell-o.

I've rebuilt carbs from the 80's that now run fine, so that is probably just what you need to do. Especially with gas that was that old.

Get a good manual, tear apart the whole carb, clean it all out with carb cleaner and blow out all the jets Then replace everything (use new rubber stuff if they are in bad shape) and set it back to stock if your bike is stock or whatever setting you need. It should work much better after that. Then you can tune it.

 

Yea, it wont idle without the choke out. And when I'm not accelerating it jerks a lot. A few times it actually was jerking real bad during acceleration. The throttle response is EXTREMELY slow. So much that I can pin the throttle from idle and it takes about 3 seconds to rev AT ALL. I'm thinking its a combo between bad fuel, clogged carb, maybe even clogged petcock and/or fuel filter. It runs ok, minus the idle problem for the first couple of minutes after start up. Then its downhill from there. How hard is it to flush out any gunk or dirty fuel from the tank. I dont mean just running fuel seafoam or something like that. I mean literally FLUSHING it. I'm actually thinking of just going with a new Mikuni 42. I hear a lot of good things about them and if its going to cost me over $100 just to 'tune up' the stock stuff myself, I'll just do a new carb. The thing IS 18 years old. Any more input on the Mikuni 42?

 

Sounds like all it needs is a thorough cleaning and to be adjusted correctly. Thats exactly the way it will run when rhe jets and air bleeds are crudded up. Those CV carbs are one if the best carbs available and rarely have to be replaced. They are very easy to work on. Tons of info on the web.

 

Sounds like good news. I need it to run right before monday morning. i have to take a damn on base safety course because the marine corps is picky about that crap. it just needs to quit sputtering and jerking on me.

 

It could be the idle jet is blocked, or partially blocked, or the float level is low. To drain the tank disconnect the gas pipe at the tap and drain it into a suitable container. I personally would then remove the tank, take out the gas tap and clean it, also flush the tank to make sure it is clean inside. Refill with fresh gas. Take a look inside the carb float chamber. If it is clean, you may be fine, but if it looks messy in there, then an overhaul kit would be a good idea.

 

I agree the carb just needs to be cleaned. Pull the hose off the petcock (I do this with an extra piece of fuel hose into a can) and drain the tank and pay attention to see if it's running free. If so just refill with fresh gas and go. You don't need to dump any extra crap in the tank.

 

The carb is easy to take out and clean up. Shut off fuel, run till it dies. (well that's what I do to get the gas out of the carb) disconnect fuel line, remove A/C. Loosen Throttle cables at the grip. then disconnect from carb. loosen the choke **** and drop out of the way. pull off vacuum line off of the back and the carb should fall out by then. 4 screws on the bowl opens up the bottom end that you need to get to. Don't open the top. I had to take mine apart last week cause of debris in there killing it at high speeds. if your carb has never been off, that round rubber gasket on the intake manifold may need to be replaced if there are cracks in it. 18 year old rubber may not be in good shape.

 

This place here can help you make your carb all it can be.

Harley Performance