You are correct that parkerizing solution is good for any ferrous metal.  We have used it on Garands and various cast carb parts.  Works beautifully!Since the base of the carburetor is disassembled, there isn't too much to go wrong here.  Your best best would be to make a wooden plug and just block off each end.  You could make one for the idle mixture screw too.  This should prevent the majority of the solution from getting inside of the base.  The only hole we should be worried about is for the idle mixture screw and it is pretty large and tapered - pretty hard to imagine it being affected.  One of the carbs on one of ours jeeps was reparkerized this way (no plugs) and it works fantastically.  No issue.  Just block off the ends to be safe and you will be fine.  On the Weasel carb, there was one machined bore for a vacuum accelerator pump - we were careful to block that one but not crazy so. 

Rob - you are much too likeable!😀  We will definitely give you grief next time we see you (we may make you and Dennis drive at the back of the pack), but I do understand the choice.  We are going to do a test soon!  FWIW, I was on the phone with David Sarafan today....he said that Pertronix works great on the WLA....but....they do fail and when they do, it is a lights out failure...push the bike home.  It is cool technology for sure.

Thanks Pierre!  We will work on getting Dennis to bring his M38 up to the shop or at least get him to do a video of it.Also, we are still working on the reprint of the Oxy-Acetylene Handbook...struggling to get permission from the owners of the copyright.  It is hard to get in touch with the right people.  In the meantime, if you search the title in Ebay, you will see it for about $20 used.  Get either the 1943 first printing (cool) or the 1968 2nd Printing.

Love it Scott!  Seems like so much knowledge gets lost....then you go back and lift up the lid on this machine and all of this cool information was used to create these tools.  There is magic in understanding these old diagnostic tools!

Good point John.  I did not - but mostly because my jeep has none so it is an easy choice!  I was taught to plug the distributor advance when setting the timing (or use the advance port for the vacuum gauge) but not to worry about any other vacuum accessories - brake boosters or windshield wipers.FOD yessir! We were being loose cleaning that engine for sure.  I don't think we got any good images, but the inside of that carburetor is crusty!  We are going to have to pull the head of that engine - the valves look ugly....so I am expecting we are going to do an in frame overhaul - redneck style! 

Woo Hoo!  We live in a county that is pretty damn redneck.  They loved it!

Thanks Samuel!  Welcome aboard!

You are so welcome Andrew.  We all get so much satisfaction "reinventing" the wheel... seems like so many of the tips and tricks of working on these old machines are getting lost as the guys who grew up with them pass away.  The manuals are mostly great, but you sure learn a lot in the field, working and testing.  Enjoy!

We cleaned everything in ultrasonic, then I bead blasted everything.  The metal needs to be 100% clean.  The brass (aluminum) is not affected by the parkerizing solutions so you can leave the plug in place.  I don't think most of the kits come with replacements for those plugs in particular so unless you are sure, I say leave them.  It is a cool process - you are going to love it.

You are welcome Kent!  Thanks for being here!