Carb rebuild

Russell Reay

Well-known member
I have a Zenith 2, a rebuild kit, and the red book open on the bench. Two problems so far. The venturi is stuck very firmly into the top body. I have tried tapping the top of it, but there is too little gap to get a good contact with a drift. The book says heat may be needed to remove the venturi from the bottom. Will it harm the parts--esp the top body--by using heat on it? I am thinking propane torch, not acetylene. Two--the screwdriver slot on the main jet has been damaged by someone--probably unsuccessfully--trying to unscrew it. Now I cannot get enough purchase with a screwdriver to accomplish the task. It is now soaking in a bath of mineral spirits. Would heat help with this issue?
 
I have a Zenith 2, a rebuild kit, and the red book open on the bench. Two problems so far. The venturi is stuck very firmly into the top body. I have tried tapping the top of it, but there is too little gap to get a good contact with a drift. The book says heat may be needed to remove the venturi from the bottom. Will it harm the parts--esp the top body--by using heat on it? I am thinking propane torch, not acetylene. Two--the screwdriver slot on the main jet has been damaged by someone--probably unsuccessfully--trying to unscrew it. Now I cannot get enough purchase with a screwdriver to accomplish the task. It is now soaking in a bath of mineral spirits. Would heat help with this issue?
Heat for the secondary well, works great a lot of heat propane may work but not hot enough, heat the outside on carb where the secondary well goes till red hot hit with cold water and it will come out! the venturi be carefull with heat it will pop due to different metal. Heat will not harm the carb itself. Use a good penetrating oil for the venturi.Heat the carb not the venturi
 
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Heat for the secondary well, works great a lot of heat propane may work but not hot enough, heat the outside on carb where the secondary well goes till red hot hit with cold water and it will come out! the venturi be carefull with heat it will pop due to different metal. Heat will not harm the carb itself. Use a good penetrating oil for the venturi.Heat the carb not the venturi

Just discovered the shoulder at the base of the venturi. Was able to use a screwdriver and teased it out of the upper body. The secondary well came out OK. Had to use determination and be certain not to damage the screwdriver slot. My problem is the main jet. In my limited experience, heat to red hot and douse with cold water = instant crack, although I have never done this with a carb. Please correct whatever misunderstanding I may have.
 
Update--pleased to report success. Heat and cold water worked to release the main jet. Pretty soon my carb will look those on Gary's shelf
 
Update--pleased to report success. Heat and cold water worked to release the main jet. Pretty soon my carb will look those on Gary's shelf
Great!!! Heat works good on the small screws throttle and choke plate also.
 
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