Why Is This Happening?

What is going on with my ride? Yesterday, I decided to take the bike to work, it started great, pulled really hard, then all of sudden it died. I tried to start it and it just would not. Finally, I took the fuel cap off, put it back on, tried to start it, and it fired right up. I took the bike home as I was running a little late, thank God I was not that far away from home. My first impression was that there was a vapor lock condition that had occurred. I spoke with HD over the phone and they agreed, but did say that it was difficult to get to the bottom of it over the phone. I spoke to a couple of other people and they had confirmed my suspicions. All of them said that my cap was not venting, or tank breather was plugged. So I took so air, shot it up the tank breather to see if that tube was obstructed, it was not.

After all of this, I felt good that my bike would run. It started really well, idled great. I took of, everything was good, then three blocks away from house, it died!!!:gah:

I tried to restart it. It will fire, but not stay running.

Could this be an issue other than my tank not breathing properly? Is it possible that my coil is going bad? I am going to pull the tank filter an look at that to see if I am plugged there, plus the in line.

Any direction on this would be really cool because I am starting to be really frustrated and do not understand it at all!!!!:gah:

So does this sound like that it is not venting properly, or do you think that it is something other than the venting?

Just a thought, could I drill out that tiny hole in the cap to help it vent, or is getting a new one the better route to go?

OK, here is the tank that I am using, I could not get a picture of it, but it is a Drag Specialties PN ds-391352. For this you may want to check the 09 fat book if you have it or the disc. I have a link to show the cap from DS and my actual cap.

First. the image from DS, then the actual cap.


Drag Specialties

Now what is interesting is DS told me that this is the only pop up that will work with this tank. I have a hard time believing this, but at this point, I do not know a hell of a lot about bikes. Like I said, my stock cap from my other tank worked just fine.

What I'd do is loosen the cap and drive it around a bit to see if it happens again then if it doesn't tighten the cap and drive it around the same way again.

Of course, you might just have a little dirt in the carb.

I tried that to no avail. I just drained the oil and filter and there is a strong presence of gas oder. I am going to pull the in filter and see if that is clogged and maybe the tank filter. I did put the old cap on it for when it is ready to fire up. I am very determined and frustrated.

Truly sounds as if your cap is not venting and it is pulling vacuum. Is the cap harder than normal to get off, like it is being sucked into the tank?

Also did you use the factory petcock on that tank? It has that silly vacuum valve in it as well. Mine did that crap to me (though it didn't start back until I replaced the vac line on the petcock).

First thing I thought was you ride with dirtbags like I do and someone turned your gas off. Since mine has that vac valve I never turn mine off nor hardly ever check it when I start out. Dirtbag friends will shut off the fuel on me from time to time. Annoying but funny still.

Didn’t you have trouble before with stuff in the tank? There may be something stuck in the inlet channel above the float needle seat. Buddy had that trouble no one seemed to be able to find it I took the carb off and took it apart and you could barley see something (piece of tank liner) laying crossways in the channel. Took a small awl broke it up and blew it with air real good. That was 4 years ago and no more problems since then. His was starving for fuel when the piece would get turned just right. Harley had warranted his tank the previous year for the lining pealing, so that piece was in there a long time. Just saying could be that, that could also cause your float bowl to over fill if the piece got lodged the needle seat opening.

DUDE, that was an awesome question. yes it would be difficult at times to get my cap off, by this I mean that would be tough to turn to loosen it. I never heard a puff of air when I released it, but sometimes it took a lot of strength to get it loose. No I do not have the factory petcock on it. You know, when I go through this, I check to see if the valve is on, it is. I think I would beat my buddies ass if they did that to me a lot. :roflmao: What ya think?

I really do not think that it is the carb in this situation. One thing to remember is that I do not have the stock tank on. I purchased one from Drag, so the tank does not have that lining that a lot of people are talking about. As far as the float goes, yes, I had some dirt that made my float stick and caused it to push gas out of the carb overflow. Just here about a week and a half ago, I had the carb off and went through it. The carb was really clean, the only thing that it needed was a bigger pilot and to adjust the idle mixture screw.

I just got the oil changed and attempted to start it with the stock cap from my old tank. The bike fired right up. NOt sure if I want to take it out for a spin. LOL Just kidding.

Ok, I have been in touch with Arlen Ness and asking about vented caps. In the link provided is the cap that they are recommending to use. Of course it is one of theirs. I am wondering if anyone has used one of these or know of someone who has?

Arlen Ness - Peaked, Vented

That is one thing that I did not do to the cap is clean that hole out with carb cleaner and a pic. I guess I am to the point that I will use the old one for a while to see if this is really my problem. I guess this what I get for changing stuff around. Customizing is fun, but can be a real bitch at times.

Does real hot weather cause gas to vapor that much to where it would cause this condition or push gas into the crank case? I am interested in the science of this? Can someone explain this in simple english?

Well, I just took the bike out for a ride with the stock cap on it. SAME THING! I wasn't able to get the bike home so I am going to pull the petcock off right where it sits, change gas and in line filter. This just really baffles me to no end. Is gas that ****ty to where there is that much dirt in it?