tillotson 031 help

[dozerman]

Boy, I hope someone here can help tonight!

I just got an old 031 that had fuel problems. I replaced the manifold, impulse line, fuel filter and checked the fuel line and tank breather. I'm in the process of rebuilding the Tillotson carb. Being a new saw to me, I'm not sure if the carb was put together right last time it was gone through. Specifically, the diaphragm. Does the gasket go against the carb, with the diaphragm against the cover, or the other way around??? I wonder if this might have been the carb problem all along???

Many thanks guys!

-Bob

Pioneer
Mac
Stihl 031
Homelite (consumer saw...don't buy one!)

 

[PES+]

What was the saw doing?

What were the fuel problems you had that led you to open the carb?

 

[dozerman]

It fell on it's face when you put it in the wood. Otherwise ran fine. You could free rev it pretty well, but hit the wood and it fell flat. Kind of surged in the wood. like it was leaning out

 

[dozerman]

Any idea which goes first on the Tillotson?? Diaphragm, or gasket?

 

[daemon2525]

Which Diaphram ?

On the metering side, the gasket goes against the main carb body.

On the fuel pump side, the diaphram goes against the main carb body.

 

[PES+]

daemon2525 has it right order

Did you rebuild it yet? Or are you just asking before you re assemble the carb?

The metering diaphram is the one with the post that the lever slides into the fuel pump diaphram is the one with the two flaps in it that cover two holes on the carb body

 

[dozerman]

I am putting it together as we speak. In fact, I think it was put together wrong when I got it. So...just to be sure, you're saying that the fuel pump diapgragm goes against the carb body, then the gasket "spacer" goes between the diaphragm and the cover???? That's not the way it was, but that might be why it didn't run right.
Thanks again for the fast reply. You guys are awesome!! I was about to bolt the carb on the saw, put together with the gasket first against the carb body, then the diaphragm.
-Bob

 

[daemon2525]

The diaphram that has two little FLAPS on it, goes directly against the main body of the carb. Then the Gasket goes on top, then the cover.

 

[daemon2525]

The way that I remember, is to understand what that diaphram does.

It is a fuel pump and those little flaps must completely close off the corresponding hole in the main body of the carb. With the gasket under it it could not do so.

Then I remember that the other side is opposite.

 

[PES+]

If the fuel pump diaphram was installed on top of the gasket you would be lucky if it ran at all. I have seen several production runs of saws and trimmers that were mis assembled that way. Most would not run at all.

 

[dozerman]

OK ...
it was put together right. It's not the diaphragm with the two flappers. It's the other side. The side that the impulse line goes to. Sounds like that should have the gasket first (against the carb) then the diaphragm (between the gasket and the cover). Thats the way it was.
Thanks again!!
-Bob