LanceRobson

Item 2 is the bottle base for the ether start kit.

Item 3 should have a plug in it. The bottom of the breather tube should have a length of oil resistant hose to get the blow-by down below the axle tube. It'll keep things cleaner.

Item 4 is OK just the way it is.

I don't see anything that would effect idle speed.

Unless an air filter is brandy new, looking at it won't tell you much about whether the airflow through it is restricted. Is the air restriction indicator on the dash showing any red while the engine is running (at any RPM)? It it idles with no air filter, does the RPM change?

If there were an air leak that mattered I'd expect the idle to stumble and to lope somewhat. At any rate, if you want to be really sure none of the things you've pointed out are causing the low idle plug each one in sequence with the engine running.

I don't think you'll see any change. If there is no change, check the -20 manual and adjust the idle RPM. A very low idle speed is a great way to tear an engine up.

Lance