Gas tank cap question

Rob Achenbach · Nov 17, 2020

On the 129, inadvertently forgot to replace the gas cap one day and left it laying on the engine and then of course mowed it to shreds. Luckily, sort of, It’s the exact same size as a can of Oatey pvc glue. But with a small nail hole punched in the top to breathe, every now and then I’ll get gas all down the sides of the tank. Is a breather hole in the cap truly necessary? Do replacement caps have some type of breather mechanism built in? Any advice would be greatly appreciated. Thx

digger · Nov 17, 2020

Rob Achenbach said:
On the 129, inadvertently forgot to replace the gas cap one day and left it laying on the engine and then of course mowed it to shreds. Luckily, sort of, It’s the exact same size as a can of Oatey pvc glue. But with a small nail hole punched in the top to breathe, every now and then I’ll get gas all down the sides of the tank. Is a breather hole in the cap truly necessary? Do replacement caps have some type of breather mechanism built in? Any advice would be greatly appreciated. Thx

kashaver · Nov 17, 2020

The replacement caps have a baffle to keep the gas in the tank.

The last Kohler replacement I got just had a fiber washer with a hole at a different spot than the vent hole in the cap.
Not cheap, though.

digger · Nov 17, 2020

kashaver said:
The replacement caps have a baffle to keep the gas in the tank.

The last Kohler replacement I got just had a fiber washer with a hole at a different spot than the vent hole in the cap.
Not cheap, though.

Yeah, you gotta save up to buy one of those. ;-)

gary noblit · Nov 18, 2020

Not being smart"xxx" but some folks don't know...Without vent tank ends up in vacuum stopping flow of gas,engine runs out.I've had 3 that were plugged by muddobber wasps in the last few yrs.A poke with small nail and back to business.You learn a lot of crazy little things if you stay at it long enough....