Stihl CS Vent - The Tube With Two Screws In It. Stihl Techs?

[hotajax]

So I have an 021. Seems to run pretty well, except after it's been cutting and you sit her down. She idles down almost to a stop, and then catches up just before it dies. Does this every 10 or 15 seconds.
I took the saw to an old farm boy and he listened and figured out the tank wasn't getting enough air in to vent it. So he removed one of the two screws from the OEM tank valve. (The OEM fuel vent is a tube with 2 screws in it) Problem fixed. Idles fine, all day. But I'm pretty sure this valve will leak if the saw goes on it's side. Question: Is it OK to use one of newer white bell shaped tank valves? Gotta be better than the old design. Thanks in advance.

 

[HarleyT]

Sure, use whatever works.
The white bell ones are Echo style, likely aftermarket. They work fine.
One screw does fine too.

 

[hotajax]

Thanks, Harley. Came through again!!! Looks like it's quite a trick to get that second screw way down in the tube. Looks like you'd have to perform surgery to pull that off.

 

[Duane(Pa)]

Grub screws don’t vent worth a crap if they cut threads into the hose.

 

[HarleyT]

Yeah, they should be pushed in, not screwed.
I usually just use one screw.

 

[Mad Professor]

That is a simple setup that has worked well for many years on many saws.

As Harley mentioned, push the screws into the tubing. A small allen wrench works good (3mm/1/8")

Stihl manuals have depth to push each screw in. One ~ 3/4" from tank side the other at the vent end of the tubing.

If you only use one screw put it at the end of the tubing, so fines won't clog the tubing