09 Street Glide 6 gallon tank
Two weeks ago I got some bad fuel, I think. The bike started to run poorly after a fill up. I used about 3/4 of the tank then refilled it and added some octane boost. It still ran badly so I used that tank until there was only half a gallon left then refilled with good gas. It still runs bad. There must be dirt in the tank so I'm thinking I need to replace the fuel filter. Is there anything else I should do or check?

 

Try some "Gas dry", sounds like water in the tank. Octane boost does nothing for this situation. Use a brand name 93 octane gas from a high volume station, assures you of fresh gas with no water.

You could also have a spark plug misfiring, or loose spark plug wire. Go with the Harley stock plugs for best performance.

 

+1 on gas dry, don't know about the factory pug deal though!
Terry

 

I have never seen gas dry around here, that is brand name right? If I used E85 gas, that would be about the same wouldn't it? Would I just need it for one tank of gas?

 

heat its gas additive for winter use.

 

I like to do all my own service, but on this one you need to drop the bike off at the dealer. The bike is under warranty so let them figure it out. I doubt if you have bad gas if you ran through a fresh tank and still having issues. Could be fuel injectors, air leak, tuning issue. Could be anything. I wouldn't guess your way through this. JMHO

 

Just premium gasoline...

 

Running one tank of gas through it then refueling might delute it, once you get it shaken up, water seperates from the fuel, generaly sits at the bottom of the tank, which should mean that it will pump out first, but that is not what happens in the real world, I still think I would try some sort of gas dryer, ask your local parts store, it wont hurt anything, and if that is the problem you wont have to go very far once you put it in to find out.
Terry

 

Thought I had bad fuel in my 08 Ultra-ended up being a warranty issue. Factory service bulletin on cracked fuel pump housing in the tank. Tech knew immediatly what it was when he test rode it.
Take it to the Dealer

 

NO don't add E-85..or you will be having problems out the wazoo-including loss of warranty..