05 Sportster, carb, 2K miles. Always ran like a champ.

Recently, after about 2 miles of riding, when I stop in traffic it bucks, spits and backfires while trying to get going again. Eventually, through revving the throttle, it will get going.

Thought carb might be gummed up as it sits alot (wife's bike). Put carbcleaner in the fuel and ran it about 15 miles. Thought it was getting better. As I was parking it it got real bad and threw a check engine light.

DTC is P0373 CKP Sensor Intermittent Carb,and P0374 CKP Sensor Not Detected Carb

Checked wires the best I could - all seem tight. Nothing obvious with carb.Cleared codes. Ran bike about 3 miles around neighborhood and no new errors - seemed to run OK, but I don't think I went far enough to ensure it is fixed. No new codes.

I'm thinking now that I have an intermittent problem with the Crank Position Sensor.

Anyone have any ideas or experience with this before I bring it in to my Indy for some work?

All help appreciated.

Thanks,

JBB

 

Update - Bike sat overnight with the carb cleaner in the fuel. Ran it this morning and the problem seems to have gone away. Spoke with Indy today and he said theECM code was more thanlikely thrown as the bike was stalling and coughing and that theCPS should be fine.

I'll watch it for a few days and report back if there's any changes.

Hopefully, this will help someone else out.

 

Look at the bottom rear of the float bowl viewed from the opposite side of the bike between the cylinders. You should have a small brass screw there at the very bottom of the float bowl. Crack it open a turn or two and let some gas run out the overflow tube. You may have some sediment built up in the float bowl or even water. Both would accumulate at the lowest point in the bowl just where the jet is.

 

Thanks! I'll check that out if the problem continues.