Factory carburetor metering lever settings

[Chainsaw Jim]

It was on an 034. The Stihl manual did not show a Tilotson. I set it up like a Zama C3 since that was the only way the manual showed it. The saw ran fine. I just like to know right spec. I'll remember to set it up like a WJ next time.

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The 034 carb should be like the two on the right side of my pic, not the WJ or others on the left. It should be a C3A.

 

[Chainsaw Jim]

I've been rebuilding the McCulloch flatback primer carbs with the only kits available which are flatter and have less travel than oem as you see in the picture.
Oem on left, aftermarket on right.

After adjusting the metering lever to compensate for the stiffer design it ended up right here as pictured. It's approximately .010 above the edge of the carb body.
With this in place the lever is not in contact with the tab on the diaphragm and allows perfect idle settings.

 

[Chainsaw Jim]

I've been rebuilding the McCulloch flatback primer carbs with the only kits available which are flatter and have less travel than oem as you see in the picture.
Oem on left, aftermarket on right. View attachment 54961

After adjusting the metering lever to compensate for the stiffer design it ended up right here as pictured. It's approximately .010 above the edge of the carb body. View attachment 54962 View attachment 54979
With this in place the lever is not in contact with the tab on the diaphragm and allows perfect idle settings.

These kits don't come with new metering pins. The larger ones from most carb kits are easy to modify to work. You can chuck one up in a dremel or rotary shaft grinder to mill it down by spinning it while holding a flat file up against it or whatever's clever.
Here is a pic of an oem pin below. It's the one closest to the ruler.

 

[Poleman]

GREAT info Jim.... I'm glad you pointed out the differences in the diaphragm nubs. There are a couple different kinds and lengths to watch for as you've shone.
Dall great link for Tillys also!!!

 

[Chainsaw Jim]

These flatback carbs seem to be in the ballpark of 1 1/2 - 1 3/4 turns out on the low, and 3/4 to 1 turn out on the high.

 

[MattG]

Good thread! Subscribed