Sachs Dolmar Injector Carburetors

[Kensie1988]

After reading Mr. Marks post and learning a little bit about the Sachs injector carbs it got me wondering how exactly it works, does anyone have any literature or can break it down and explain it to me, that way if I ever need to make repairs on mine I know what going on internally.

 

[RedneckChainsawRepair]

Jim gave a idea how it works in first post. https://chainsawrepair.createaforum.com/dolmar/dolmar-6000i/msg53515/#msg53515

 

[Bwildered]

I've got a dolmar 120si, the choke operates a valve that opens when the lever is turned anticlockwise , it's a simple cam operated valve, once opened fuel is drawn via vacuum into the throat of the carby from the second stage of the fuel system.
Thanski

 

[kevin j]

so basically it sounds like it works like the enrichener system on the Mikuni motorcycle carbs. is that correct?

 

[Modifiedmark]

I've got a dolmar 120si, the choke operates a valve that opens when the lever is turned anticlockwise , it's a simple cam operated valve, once opened fuel is drawn via vacuum into the throat of the carby from the second stage of the fuel system.
Thanski

I ended up pulling the valve out of my carb to see what was going on with it as it would flood badly and not run at all.

It is cammed like you say and rotates counterclockwise in use but it appears it would work clockwise as well if orientated that way.

There is a rubber tipped needle on the end that closes off a hole in the carb body. The problem with mine was the valve was not seated fully into the carb body so the needle would not reach far enough to close the hole in the carb body.

By the IPL I have it appears there were 3 different versions of the Tillotson 236 carb, 236A, B and C. The difference is the injector valve and the way it mounts to the carb body.

Mine is a A carb and the valve is just press fit into the carb. The B carb valve shows a roll pin used somehow while the C carb used a valve with a tab that a screw went through to secure it to the carb body.

I can sure see why they wanted to change from the original A style valve.