Newb with a B&S generator engine

[sparkydave]

Hello all, I have an old Black & Decker generator I've been resurrecting, and it has a Briggs 5 HP engine, type 130232-0169. I've got it repaired and running, but it has one annoying thing that I haven't been able to resolve yet. The gas cap oozes gas. The lip isn't bent, and the cap seems to tighten OK, but with the fuel sloshing around from the vibration, it eventually gets wet around the cap, and trickles down the side of the tank. I've tried making a new gasket out of rubberized cork material and out of gasket paper, but no improvement. It looks like in both cases, the lip of the tank left an even groove in the gasket, so I'm pretty sure it's sealing evenly. Any ideas?

 

[DaveTN]

Hi and Welcome to the LMF! Maybe the threads on the tank lip and the cap might be rusted etc. ?

 

[Rivets]

Those caps had full cork gaskets like this one. The full gasket reduced the leakage problem. Briggs # 394818S. https://cdn.shopify.com/s/files/1/0128/2336/3684/products/pneo0time7ulozvahhqy.jpg?v=1587625107

 

[sparkydave]

Thanks, so would cork be a better material to use? The old one isn't cork, but more like a cardboard material. The gasket paper seemed to work until I poked a small hole in the center for a vent. I suppose I could order a new cap, but it seems like the gasket in the old cap could be replaced. No rust in the threads.

 

[sgkent]

is the cap itself vented or unvented? My briggs caps have a deflector down inside that causes fuel being splashed to remain in the tank.

 

[Rivets]

If you lookup the part number I posted, you’ll notice that both the gasket and cap are vented on these older style setups. At the time these were used, this was the way to reduce splashing.

 

[sparkydave]

So here's a picture of the gas cap with the old gasket. It's grooved from the lip, but if I slip in a different gasket that's cut to the same size and has even a small hole in the center, gas still eventually seeps out from between the threads. If I don't poke a hole or make one that's too small, it either stalls after a while, or I'll shut it down and a minute later the heat from the muffler causes the tank the heat up, which then forces gas into the carburetor, which floods it and leaks out from the choke pull.

 

[Rivets]

Sounds like you need a new cap.

 

[sparkydave]

OK, but are the threads supposed to contain the gas? Trying to figure out how it's supposed to seal if a new gasket doesn't seem to fix it, unless the gasket is supposed to be glued to the cap somehow.

 

[bertsmobile1]

The original gasket is bigger than the hole in the cap so it is held in there like a welch plug in your engine block .
Over time the shrink or go soft & fall out