rcnats

My Feedback: (56)

Help! I have a ST 4500 converted to gas. I have a Walbro WT 446 carb on it. I wasn't drawing fuel with the choke so I soldered over the hole on the plate. I worked the choke and it moved freely. The next day I was going to run the engine on my test stand when I noticed that I could not move the choke...it was "frozen" shut! [X(]I tried and tried but I cannot move the choke. I was able to remove the plate and do not see any solder anywhere around the lever. I tried using pliers and it will not move. Any ideas? Suggestions? Can the choke rod be removed? Thanks in advance.

SkyPilot101

Sounds like you over heated it. Wet the shaft with premix were it passes through the carb body, followed by a few drops of oil and gently work it free.

Lnewqban

Yes.
The heat deformed the aluminum body somehow.
Try heating the body with a heat gun or in the oven.

Check the schematic:

w8ye

My Feedback: (16)

The heat could have hardened some oil or what ever in the pivot area of the shaft.

As has already been said, a heat gun will likely loosen it up.

Rocketman_

Maybe soldering flux leaked between the shaft and the carb body.

rcnats

My Feedback: (56)

Well I soaked the carb in premix for 3 hours. Allowed it to dry, and put the heat gun to it. The first time I did it for 30 seconds. I was able to move the shaft a little bit . Next I held it to the heat gun for 1 minute, used the pliers and it moved both ways!!! . I'm letting it cool down now but thanks to all who responeded. This is one for my "lessoned learned".

SkyPilot101

Oil that sucker up! Two stroke oil is fine.