Originally Posted by

David Martel wrote:
James,

These things are generally in two groups: the three screw group and the
two screw group.

(I can confirm it's a two screw carb).

Let's take the two screw group first. You'll need a screw driver and a
spray can of starter fluid (ether). The two screws are a mixture screw (the
needle valve) and an idle speed adjustment. Screw the mixture screw all the
way clockwise and then back out 1 1/2 turns. Give it a shot of starter fluid
and start it. Adjust the idle speed if necessary so that it runs at idle.
Let it come up to operating temperature. Now adjust the mixture screw
counterclockwise (you enrich the mixture). It should begin running quite
well at some point, continue adjusting the screw ccw and it should begin to
run rough. Note this position. Turn the screw cw (you lean the mixture)
until the idle becomes rough. Note the position. Usually about half way
between these two positions is the proper adjustment. You may need to fine
tune slightly. Now that the mixture is set adjust the idle speed screw by
reducing the engine speed at idle until the engine almost stalls. Increase
the idle speed slightly above this and you are done.

Where would I give it the starter fluid? Have played with the needle
valve and got it to the point where starts but it won't ever tick over
until operating temperature is reached. Which
(clockwise/anti-clockwise) raises the idle speed? I take it that the
idle speed screw is an "end-stop" which prevents the revs from dipping
too low when the throttle is lowered to it's minimum point? An
observation is that the springs don't seem to have much "springyness"
anymore and it never reaches the point where the screw touches metal.

Thanks for the ideas. I will probably have words with the local B&S
dealer about springy springs, seals, diaphragms, etc.


Good luck,
Dave M.