The Stovebolt Site Forums The Shop Area Engine Shop Replacing the zenith carb ?

The old Zenith carb on my 248 has a rusted solid throttle shaft. It’s soaking in WD40 but I don’t have much hope. Obviously hasn’t run in years but I’m pretty sure the engine is ok. What’s a good replacement carburetor without breaking the bank ? The previous owner had the carb off and exposed to the weather.

The Zenith carbs for the 248 are much more common, and much less expensive than those for the 270. Not much available (ever) that is better than the Zenith. I would suggest, if you wish to replace it, find another Zenith with the same tag number (assuming that the Zenith you have is correct for the application).

WD-40 is probably not going to free the frozen shaft. Remove the throttle body from the rest of the carburetor, and remove everything you can remove. Now, heat the throttle body as hot as you can in an ELECTRIC toaster over (DO YOU USE A GAS OVEN!). Remove the evenly heated throttle body from the toaster over, and with an acetylene torch, spot heat the casting where the throttle shaft goes through until cherry red on both sides. Set it aside for an hour or so and allow it to completely cool naturally. DO NOT QUENCH IN WATER!. Now, gently try to work the throttle shaft, using the WD-40 as needed.

Jon.

Just curious, would soaking the effected area in Evap-o-Rust overnight help?

Martin - I don't know, but don't think so. I don't believe it would penetrate the rust between the shaft and the body, just like the penetrating oil will not penetrate the effected area. Be interesting to try.

The heat burns the oxygen from the rust molecules between the shaft and the body, thereby reducing the volume occupied by the rust. This allows penetrating oil to penetrate the now porous rust, and allows the shaft to rotate.

I have been using heat successfully for more than 50 years on cast iron throttle bodies.

Jon

I use some stuff called deep creep. I the same company that makes sea foam makes this stuff. They say heat and then use the deep creep. I just freed up a heat riser shaft using basically the same procedure as Carb king described but used deep creep. It took a couple days of soaking and repeating the process.

Kroil is the best rust-buster out there, bar none!

www.kanolabs.com

Jerry

Thanks for all the suggestions
24 hour soak in 50/50 Acetone ATF no affect Kroil for a few hours before heating with torch.
It broke loose. Now working great.
The metal accelerator pump was tough to get out. But finally got it out with no damage to carb body.
Left the check valve in until I get a rebuild kit hopefully it will be included.
Who makes a good kit for a Zenith 228?

Glad the torch worked for you.

You will need the inside number from the round tag to acquire the correct rebuilding kit.

Our various kits for the various 228 carbs all include the check valves (2).

573-392-7378 (9-12, 1-4 Mon-Tues central time).

Jon.