Gas Cap Blues....

[Vince Lupo]

So I just spent mucho $$$ to get my tank, front fender and side panels repainted. I went to fill my tank last week, and found that the paint lifted a bit around the filler cap. I read somewhere about a 'fix' for this phenomenon, which was to seal the paint edge near the filler hole with Krazy Glue. It seems to have worked and the Krazy Glue seems impervious to the gas, but I'm trying to figure out why my relatively new rubber gas cap gasket is always wet with gas when I remove the cap. Is the gasket the culprit? Is it the cap? Is this just the way it is with these caps?

I can't quite figure out how this cap is supposed to vent. This is the original (flatter) cap with a rubber gasket that I bought a couple of years ago (this replaced the old cork gasket).

Any suggestions? Any value to drilling a small hole in the top of the cap to have it vent that way?

[rustywrench]

I'm not sure about the cause of your particular problem, but these caps are vented and over time they can become plugged. My first cl quit running one day and when I opened the tank to check the gas level, it sucked fresh air. The two parts of the cap do indeed separate and you can tell if the holes in the inner part are plugged. Mine were, end of problem. Also, I prefer the cork; personal choice I suppose. Good tip on the paint seal though, thanks. RW

[davomoto]

Vince, take a good close look at the inside of the cap, where the rubber gasket is, just outside of the gasket, you will find a small hole. That is the vent. So.... Hondas design for the vent drips fuel onto thwe tank when the fuel tank is full, or it is sloshing about during more spirited riding. Some of the on/off road Hondas of the seventies had a gas cap that was vented in the center, with a nipple on top, connected to a rubber hose that usually runs through a hole on the sterring stem nut, much like a modern dirt bike uses. And yes, one of these caps will fit a CB/CL, think mid seventies XL250/350. Unfortunatelly this is not a very good looking set-up, but very effective in keeeping gas offf of your fresh paint

davomoto

[cknight]

Hi Vince, also make sure that the sealing lip on your tank is flat, so that the gasket will seat properly. If it's warped a bit, that can cause leakage from the "low" area. Using a flat disc with slightly larger diameter than the lip, and a set of feeler gauges, should confirm trueness. The late model replacement "high dome" caps don't seem to be as prone to weep fuel, as the original low profile ones. I'll usually go riding with the high cap, and when it comes time to display, put the old one on. Regards, Chase

[Vince Lupo]

Hmm...lots of good food for thought. I do have one of those 'high dome' caps, so maybe I should try that. BUT, I do like the look of that cap with the nipple in the center. Davo, do you happen to know the part number for that cap?

Maybe my riding is too 'spirited'!

[davomoto]

Vince, here ya go. It looks like about $35 retail from your local Honda dealer.

davomoto

CAP, FUEL FILLER
17620-428-020 (replaces 17620-373-010)

[Vince Lupo]

Well I'm taking a bit of a stylistic leap here -- I called Terry at Western Hills today, and he managed to track down one of these caps, the tube, and the tube clip in the warehouse. Remarkably, it looks pretty close to a SuperHawk cap, and he tested it on a SuperHawk there at the shop and it fits perfectly. So, I'm gonna give this vented cap a try.

So, in your opinion, where should that vent tube go? If I had it go into that cutout area at the very front of the tank, where should it go from there? Could it go underneath the tank through the channel?