Re: Oiling issues and hole in air filter lid.

Posted by DavidPackard On 2023/9/21 20:25:35

Fourbybud

You wrote “Now when warmed up so much oil goes down the fill/breather tube that is blows back up into the cap and is spilling out? I'm thinking it needs a restriciton [sic] somewhere?”

Unless the drain tube is very close to a baffle, the short answer is yes. HH56 added the recommendation is a 5/64” orifice. I would place the orifice between the engine and the filter housing, because that would dramatically reduce the pressure in the filter housing, thus reducing the possibility of a gasket leak. Plus if the orifice is right at the engine, again as HH56 noted as the preferred configuration, the entire accessory equipment could fall off and you still only have a 5/64” hole leaking oil . . . not that that is acceptable, but is surely better than a ¼” hole.

If you solder and drill an orifice you might start a bit smaller than the recommended size, and re-evaluate the splash-back in the filler tube. I have some experience in drilling leaded carburetor jets . . . my advice would be don’t push too hard, if you do it makes something more like rifling than a smooth bore. I don’t think in your application rifling would matter at all, but in a carb jet it has a tendency to alter the jet’s flow and exit pattern. I have a carb jet flow rig (water not gas) for volume flow measurements. The rifling would put a twist in the flow, and direct the water flow off to one side.

With respect to the hole in the air filter. I’m at a loss, but I do have a question. Would the hole allow debris, or liquid to be directed into the throat of the carb? If it does I would find a thin fender washer to put under the wing nut while we’re gathering more information. Perhaps there was a tab washer that had a dimple that fit somewhat into the hole and allowed an anti-rotation feature for the wing nut . . . but that’s a SWAG!

dp