'48 Cub crankcase vent

[phill_mi]

Greetings; I have a '48 Cub, 6v with Mag and no TC. Plans to try and get this cub moving quickly have deteriorated significantly in the last few days. I removed the carb and ordered parts. While waiting I removed the valve cover and started to clean sludge and adjust the valves. That resulted to removing the hood, and now more tasks and waiting on parts. All of the D-21 sparkplugs were very black with carbon. So new ones are on order. I put a little seafoam in each cylinder and hand cranking compression with the sparkplugs loose in the holes, while adjusting valves, increased significantly contrasted with prior to adding the seafoam. But I will wait to pull the oil pan, clean it, and change the oil before trying to do a compression test. On the topic of the crankcase vent, I have seen reviews that it never worked very good and some advise removing it. Still pondering that suggestion while I try to clean out the tube. But I noticed that the fitting with the small hole (orifice ?) was up on the breather, when some folks say it should be down on the engine. Did not find information on this in the GSS-1132 Fuel System or IH service manual. And somewhere I read that some folks drill out the smaller hole (orifice) vs removing and plugging the hole or vs leaving it as designed. Any thoughts? Thanks Phill

[Eugene]

I wouldn't bother to clean it. If you tractor has blow by, it will plug up again shortly.

If you want the tractor to look original, just leave the tube installed.

[Gary Dotson]

The tube is not very effective but it can’t cause any issues, being there. I guess I’d kinda lean toward drilling the orifice, in an attempt to increase it’s effectiveness. It might decrease the amount of vapors from the oil fill cap.