Stihl 009L Mystery Carb Screw

[ChillyB]

Cleaning out the crapulance from my new-to-me project saw. Found this li’l tiny screw among the debris.

I also see the tank vent not plumbed, though I see the remnant of some tubing in the hole in forward starboard corner of the air box. So maybe the rest of it is still down under the clutch somewhere.

anyone recognize this itty bitty screw?

 

[Aknutter]

That's one of two screws that are inserted in the tank vent tube

 

[Aknutter]

The tank vent consists of a piece of fuel line with the screws inserted in the line, then that is connected to the tank barb

 

[Aknutter]

Google 11173505800

 

[ChillyB]

So there are screws run into the tube ID? Purpose is to effectively reduce the ID, like an orifice?

 

[ChillyB]

And, you guys are impressive. To know what a tiny screw is for on a 40 yr old saw.

 

[Aknutter]

Pretty much. I don't know the hose I'd but it's 2.5" long. Look through the remnants of the gunk you cleaned out and you'll probably find other screw. One at the end and one about an inch in.

 

[Valpen]

So there are screws run into the tube ID? Purpose is to effectively reduce the ID, like an orifice?

Yet the screw threads do not completely engage with the hose inner wall, thus allowing a tiny bit of air to pass thru that gap so that it "breathes/vents"...

 

[Mad Professor]

Back when things were simple and worked well.......

Those are known as grub screws for tank vent lines. When you replace the line don't screw it in, push it. Otherwise the screw will cut threads and tank won't vent.

 

[HarleyT]

And, you guys are impressive. To know what a tiny screw is for on a 40 yr old saw.

When you get old enough, all you can do is remember a good screw.