Hi All;

I have a 2001 Fatboy, fuel injected. Whenever I fill the tank up all the way, the engine will cut out within a mile or so. It shuts down for a second or so then comes back on misfires, etc, then after maybe a minute or so of cutting out then coming back on, it will clear up and run fine.

It ony seems to do this when I top the fuel off. If I leave a few inches of space it does not happen.

I recently replaced the fuel filter and hoses inside the tank. Doing this seems to have eliminated the other problem where it started stalling at anything under a quarter tank, but it had no effect on the cutting out when filled to the brim.

It has done this for years and I have just sort of lived with it, but I would really like to understand why this occurs.

Appreciate any feedback.

 

Sounds like it could be creating a vacuum, did you check your gas cap to make sure it's still venting?

Steve

 

+1 What he said. On a full tank and little air space it will react faster than a larger volume of air above the fuel. Vent might be working but not near enough to keep the pressure up in the system.
Ron

 

Not sure how to check if it is venting, I though these caps were non venting. There is a vent line in the from of the tank which goes down to an evap canister (california model).

Are they supposed to vent or be under pressure?

 

Yes, they are vented . Air comes into the tank as fuel is burned at the fill cap. One way valving. The tank will at times have slight pressure in it but eventually this pressure will open other breather you speak of, but this is exhale only as it's one way as well. The slight pressure is cause from a spring loaded valve on the vent line.
Pull the cap off, clean it and use the tried and true wrap the mouth around it and suck, don't blow method. You will know right away if its pooched. Wow, just reread your first post. You put up with this for years???
Ron

 

Ron;

I will give that a try. Yeah it has been doing it for years but more of a nuisance than a real problem, since it always cleared out pretty quickly.

Thanks for the advice, I will let you know how it works out.

Mike

 

Well I checked the gas cap as you suggested. It seems to vent fine and only in one direction. Just to be sure if it starts doing it again I will loosen the cap so it can breath fully. Could be I just need to leave an inch or so from the top of the tank.

 

Mud daubers or just crap likes to get into small holes. They all love vent lines that really just open somewhere to the atmosphere.

 

My CA bike does that too (07 ultra) was told that if you fill all the way up it runs into the smog canister and the canister dont like it. Sorry for the technical description (hehe) but its the nature of the beast. Just back off 50 cents worth or so, dont ask me how I know....

 

Yeah, I think just filling it less is my solution. The gas going into the charcoal canister is probably happening, maybe it is then geting sucked back in to the fuel injection and it does not like that.

Thanks to all who have replied with suggestions.