Posted by Gordon Maney [76.76.230.60] on Tuesday, September 24, 2013 at 11:16:56 :
In Reply to: No ideas on the WA-1 carb adjustment? posted by Sherman in Idaho [24.32.202.166] on Tuesday, September 24, 2013 at 10:01:58 :
High speed adjustment or main jet adjustment screws will look much larger physically than an idle mixture adjustment. In most cases they will have a jam that And it may also have a packing like a valve.. Turning the screw might involve engaging with the slot with a screwdriver, and some have a Tee handle, although small.
Start the machine, get it warmed up, break the jam nut loose, and move slowly through a range of motion, one quarter turn at a time. Count out loud to yourself so you will know where you are at all times .See how far you can go before it falters. See how far out is income before it falters. In crude terms, you'd like to end up in the center of that were it runs the best.
This experimentation needs to be occurring at a mid throttle point. Don't blow the thing up, but you have to be well about idle so the idle circuit is not functioning.
Prior to doing all this it would be advisable to observe where the screw is at the beginning — count the visible threads. Then, back out carefully counting turns to more accurately be able to put it back where it started. Be sure to shut off the fuel before you do this because you will drain the float chamber and if the fuel line is on you will drain the tank.
Visually inspect the end of the screw, it will be a fine tapered needle. Examine it for damage and correct it as possible.
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