New Evo owner. I have a 97 Badyboy and my left tank doesn't empty on ly the right one works. Hell i didn't even know that the left gas cap came off. My last bike was an 04 and they told you not to touch the left cap because of the fuel gage.

Also, after i removed the dash to have a look see what was going on. I found a what appears to be an overflow drain on the right half tank was melted off????


I don't understand why the left doesn't drain because that is where the petcock is attached. You would think the right would stay full and the left would drain!

Help please
Jamie

 

Where was this "overflow drain"?

You should have the petcock opening on the left tank, a fitting on the lower front of each tank that are tied together to allow the fuel to equalize between the tanks, and a fitting on the upper front of each tank that are tied together to allow the left tank to vent as only the right cap is vented.

If the top crossover line is kinked or otherwise plugged the left tank will not vent or be forced to vent through the bottom line. Usually something like this results in a crappy running engine, though not always depending on the severity of the blockage in the vent.

Just to run through a scenario - When you fill up, you should remove both gas caps. Next fill the left tank and replace the left side gas cap. Next fill the right side tank and replace the gas cap. Go for a good ride and then stop with the engine running and the bike upright. Pull the left gas cap off. You should not hear/feel any vacuum/sucking sound. Note the level in the left side. Pull the right cap off and note the level in the right side. The levels should be pretty close to equal. If you shut the bike off, put it on the side stand, and then look (especially after any amount of time) the left tank will appear full while the right tank will be low. This happens because the fuel in the right tank is at a higher physical level right after you first put the bike on the stand, so it flows into the left tank to level itself.

 

the overflow or maybe a vent was under the dash on the top of the right tank.

I have completely emptied the right tank and the left stays full! The bike spits and sputters a bit I thought it was because the owner before me put on some screamin eagle pipes and didn't jet the carb.

 

OK, I maybe have found a missing bit of info on my part. I have a manual that's good to 1990, and another one that covers only 1999. The 1999 manual shows a continuous vent line that goes from the tank to a vapor valve on Californication bikes, and to the atmosphere on others. Unfortunately, the pics don't show the attachment point on the tank, and don't show the routing. There is a warning to route the line away from hot things so it doesn't melt. It sounds like you have a tank venting problem, and your statement of a melted line fits that.

 

Thanks for all the info. I'll definately have to get a book to figure this problem out.

 

the left tank has the petcock, how could it not be emptying? unless the right tank is feeding directly to the carb front the front crossover line.

 

That's what was confusing me... you would think the left tank would empty out if it is not venting and the right would stay full??? I don't know but it really blows my mind!