This morning I rejetted my stock Harley carb with a 185 main jet and a 46 slow jet from the 170 main and 48 slow jet that was in the carb when I bought the bike. I got it back together and took it out for "research" and everything was doing fine. This afternoon after I ran it down the interstate and stopping at friends for about an hour, I left there and when I started accelerating in first it sputtered, then surged and then finally when I got to the high end of first it started acting right. Shifting to second I experienced this same situation as I did in first, sputtering then surging. I went back to the house opened the carb up and changed the jets out back to the original and got the same results with them. I came back and reopened the carb a 3rd time and tore it all the way down and soaked the entire thing in carb cleaner. I sprayed all the orifices out and then reinstalled the new jets. It seems like it doesn't want to idle as well and it still has this sputter/surge at low acceleration. This is the only thing that has changed since yesterday and I rode 75+ miles yesterday evening and it ran great. Well I bought gas as well. Any ideas?

 

sorry i f orgot to say that the bike is a 02 1200xl

 

Just a thought. Did you adjust both cables?

 

Well I thought i had. Would the little throttle lock down star being MIA have anything to do with that ? Also I need to readjust as I was just noticing that my throttle is sticking open when I go wide open.

 

Did you follow the correct procedure for adjusting the mixture screw when you changed the jets?

 

you should probley have the star on there...you paid for it.

 

guess i'll be getting another. It's gone. And no I didn't adjust the mixture screw. I suppose that'll be my task for tomorrow. Thanks for the input and I'll post the outcome.

 

Got another friction screw. When I opened the throttle control up there was no friction pad. I went ahead and lubed the throttle cables with teflon based lubricant and left the friction screw off until i can go get another one at the shop. i didn't get around to the idle mixture screw yet but as i took it out to test the throttle i noticed that blue flames were coming out the end of the drag pipes. i believe they are bassanis. well the blue flame is accompanied by exhaust popping of course and i noticed a couple of carb farts as well. I guess that idle mixture screw IS important.

 

OK. I got the idle mix screw adjusted. I'm still experiencing the same issue i was before. Off idle when I start to open the throttle, the the bike bogs down and sounds like it is only running on one cylinder. If I give it more gasit smooths out but if I try to WOT it hesitates then accelerates. It does this in 1st, and second and a little in third. THis only happens if I dump the throttle. If I roll on the throttle with less force it seems to do less of it but it still seems to be running crappy just as I am engaging the clutch. When the bike is idling and not in gear, it thumps away and when I give it gas it doesn't hesitate at all. Could this be a clutch issue and not a carb issue ?

 

The friction srew has nothing to do with anything you're experiencing. What does it do sitting in neutral and you give it gas? Same thing, it's not a clutch issue. Why the jet change? A 170 main and a 48 slow is not so out of spec for a stock Sportster; try the 170 main with the 46 slow, 185 & 48 a bit much unless you're running drag pipes and SE A/C. The idle mixture screw should start out about 1 1/2 -2 1/2 turns out to start. Is the accelerator pump squirting gas into the jet needle when you hit the throttle? If not, check for a missing spring. You could have knocked the float bowl out of spec changing jets and the fuel level is too high or too low (one of my choices). The diaphram could be pinched or torn. Enrichner valve not seated. The throttle cables may not be adjusted correctly (or this for my choice). The intake manifold maybe has a leak. Are you using a service manual? It's all there: carburater adjustment and rebuild/setting in Chapter 4.