tillotson md68b questiions

[seahuntboater]

Greetings. Just got this carb mostly broken down and cleaned. The float seat screw is butchered pretty good and I don’t know if any replacements are available . I polished the seat with qtip in a drill with some compound and it looks good. The needle looks good too . But on these old carbs does a metal to metal seal work? What do you guys do? Retrofit? etc.
Does anybody have a better diagram more specific to this carb. All I found was more generic on Ebsco through my library.

Also is it possible to use nitrile o ring for bowl glass? If not any inexpensive substitutes

thanks

Ralph

[frankr]

New float valve needle & seat are available at http://martinoutboards.com/

Yes, metal to metal was the norm back then. But they gotta be dang nigh perfect.

Sure, an o-ring will work.

[seahuntboater]

Thanks Frank

[amuller]

It has sometimes been a practice to tap the needle (not too hard) to cause it to mate with the seat. (or, rather, form the softer seat to the steel needle). That can make it better or worse. Since you are going to some trouble here, you could bench test the carb for leakage, setting up a gravity feed tank (old lawn mower tank…) give it a couple of feet of head and see if it holds.

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