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Electronic choke or automatic choke

M

makomike1

Contributing Member
I have crusader twin 350 270 hp with rochester quadjets with automatic chokes.Need to replace choke but screw in manifold holding assembly is rusted, cant get out.. How do I replace choke or should I switch over to electronic chokes. Pros and cons if I switch to electronic? or instructions on getting rusted screw out of manifold. Thanks Mike
 
Either type of automatic choke uses a "Helix" to close/open the choke chimney plate.....
One warms the Helix via manifold exhaust cross-over heat..... the other via an electric eliment.

Can you post a few photos?
I'm not sure that all are adaptable or interchangeable.
 
Without changing the carb, the replacement choke - either style - will have to go back where the original one sits on the manifold.

The only drawback to the electric units is their cost - they aren't cheap last time I looked. The electric ones will open much faster, especially if your crossover passage has accumulated the normal carbon buildup.

As far as getting the old one off - nothing special - just like any other rusted fastener. Penetrating oil will help as will heat (be CAREFUL using heat around the carb and be VERY CAREFUL if you remove the carb). If the head of the screw snaps off, you can always drill it and retap it. There's plenty of iron on the mounting pad - just don't go too deep.
 
I read thru somme of Doug Roe's book earlier. He indicated they are sometimes mounted with thread retaining compound - probably a good idea to use some when you reinstall the new one as it will help minimize any moisture induced corrosion in the threads.
 
DD - if he keeps the 4MV and gets an electric choke coil, how would you suggest he can eliminate the mounting screw?
 
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