Was cleaning and setting the float on my 8N the other day and noticed that the throttle shaft has some play to it. Does not seem to affect the running noticeably, but still seems it should be tighter. I believe it is the Marvel/Schebler carb. Any suggestions as to doing this, sizes or where to obtain etc.? Thanks in advance.

I've installed bushings in five old Marvel carbs, it's very easy if you have a drill press and a good cross vise.

Using a 1/4" drill bit, center up the throttle body in the vise and without moving it, swap out your bit with a 5/16" and drill out the holes for the shaft. The new bushings will tap in easily and you will probably have to ream the bushings after installing or lightly sand the throttle shaft so it moves freely without binding.

Just8n's has the bushings, you might want to check with Derek to make sure that 5/16" is still the correct bit to use, it's been a few years since I've done one.

Ok, Paul.Thanks for the info.

Vintage Ford tractor carburetors do not have throttle shaft bushings and most are well worn allowing air into the throttle venturi.

This condition affects engine operation little aside from idle where such leakage overwhelms the idle circuit preventing engine idle at specified 400 - 450 RPM.

One could bore out the cast iron carburetor shaft bores and install bronze bushings but doing so is quite a lot of work simply to restore specified engine idle.

You may have noticed the "murvel shurville" carb is a cast iron unit. Most newer carbs were a pot metal set up and the steel throttle shaft that ran through those tended to wear out the pot metal housing a bit faster than a cast iron unit.
That being said, your probably not going to find a bushing kit due to them not wearing out such as the pot metal carbs do.
You should always feel free to make your own.

Mine must be an aftermarket carb. It is definitley not cast iron, and has no markings or tags on it identifying the maker, only a ser.(?) # on the throat.Probably leave it alone. Doesn't seem to be a huge gain vs aggravation to be had. Thanks for the response.