MA3-spa carb pictures, Wagabond notes.


In the last few days we have featured some stories on Carbs. Today I went to the mail box and picked up a package that happened to be my MA3 carb returning from overhaul.  It was gone about two weeks.


Above is the MA3, freshly overhauled by D&G Suppy in Niles MI, (269)-684-4440. This is the FAA fuel system repair station that is run by Russ Romey. We have been sending builders there for 10 years. He is an excellent source of rebuilt MA3’s and Stromberg NAS-3s.

Several points here; It is hard to see, but the carb is sitting on my receipt from Russ. Although we are friends, note that the overhaul cost me the same price as he charges any other person, $650. Years ago, a handful of people on the web, led by Lon Wall of the Corvair Underground inc, frequently spread the lie that I made money and kick backs off the products I recommend to builders. This was Lon’s explanation why I suggested people shop with Clarks rather than him.

He didn’t understand that he lost the business solely because he wanted to sell builders cast pistons and old rod bolts. His claims went on the net for several years, mostly unchallenged or unmoderated. They sounded good to a handful of people who liked a good conspiracy theory or hated me since I first used the term “The Corvair authority”, (All of them missed that the acronym TCA at the time was a FAA airspace called a Terminal Control Area, and the letters stuck in aviators memories, and “WilliamTCA” my email address, predates our name “FlyCorvair” by several years.) Let the receipt be one more piece of evidence that my endorsements are not for sale.

My allegiance is only to the best interests of builders. In the last 10 years, lets conservatively say 1,000 people have built a complete corvair aircraft engine. On average, between cams, pistons, bearings cylinders, balancers, gaskets etc they spent $1,750 each on parts from a Corvair parts house.  Thats $1,750,000 in shopping. The lion’s share of this went to Clarks. I did not make a single dime off any of this. If Lon or any other parts house wanted a part of it, all they had to do was sell the parts we recommend and not offer advice like using cast pistons in flight engines. Evidently, he couldn’t do this.

Second; An MA3 is a simple carb, I have been an A&P for 22 years, I am qualified to overhaul this myself, but parts are expensive, more than half the price of the complete job. In the end, I am glad to pay Russ a few hundred dollars to make it perfect. I have no problem paying another American aviation professional for his expertise. This is how the infrastructure of aviation as we know it in this country stays in place.

If someone chooses to buy a Rotax with their two German Bing motorcycle carbs, they are only fueling the trade deficit, and doing nothing to support American manufacturing and aircraft maintenance systems. And no, a person who took a 40 hour Rotax ‘mechanics’ class is not a trained aviation professional, they are just an extension of a foreign companies sales staff.  For a reality check, my A&P training at Embry Riddle had the strict FAA requirement of 2,800 classroom hours.

If I had told the maintenance department chairman, Dick Ulm USMC ret. that I was ready to evaluate airworthyness on aircraft at the end of my first 40 hour week in the program, he would have laughed his ass off, and then punched my lights out. If I then complained to the University president, Kenneth Tallman, Maj. Gen. USAF, ret., I am pretty sure it would have had the same result. If anyone asks in 5 years why S-LSA”Light Sport category” failed live up to any of its potential to do positive lasting good for aviation, at least part of the blame will be on the fact the ASTM ‘certification’ standards on these planes are a bad joke, and the maintenance on them is done by woefully underqualified people.

Third; This carb is going on our own Wagabond, the plane that my wife will also fly, and we will bring the dog. The day it flies it will not have a radio, a transponder, a GPS, a Glass anything, an interior or a fancy paint job. Those things don’t make planes fly. It will however have this carb and it will have a 5th bearing, and a very well-built engine. Aviation is about good decision-making, and placing any of the first items ahead of the latter ones is an example of poor decision-making, and no one can offer a rational argument otherwise. Looks and tech toys come after airworthness items. If you have budget left over, add those things if you wish, but only after it is mechanically as good as you can make it.


It is a free world, and  you can use any carb you like on your Corvair.  Physics, Chemistry and Gravity also think it is a free world, and they fully support your right to make a poor choice, even one that will harm you if it doesn’t work within their system of laws.  If you wanted to run a German motorcycle carb, don’t be mad at me if it doesn’t work. I didn’t make up the laws of the physical world. I am just the messenger here to remind people that Physics, Chemistry and Gravity are great allies if you play by their rules. They are also absolutely remorseless in dealing with people who feel like the rules don’t apply to them. Be advised, if they find you guilty, the penalty phase of the system moves much faster than our criminal courts, and does not have an appeals system.

It is no secret that I like aircraft carbs. Look at the photo above, the lettering cast into the body says “Marvel Schebler Aircraft”, the logo in the middle is a propeller. This was not designed for use on motorcycles. Look at the silver throttle arm. I could literally hang the entire weight if the engine off this arm. It is not fragile. In contrast the throttle cable on a Bing carb is a tiny bicycle cable, the exact same kind that you see on cheap bmx bikes at Wal-mart. A long time ago I flew ultralights with set ups like that, and justified it by the low landing speeds. Today, I am older and somewhat smarter, and I would not fly in any plane that used a bicycle cable as a primary engine control, especially not one where the carb is going to close if the cable breaks. If the cable falls off an aircraft carb, suction alone will generally make them run at full power.

In mechanical situations, I am a traditionalist. If we are going deer hunting, no one can argue that my choice to bring a .30-06 will not work. If we were going to sea in a storm, no one could argue that my choice of going in a USCG 44′ motor lifeboat would not work. If we needed a light truck engine, no one could argue that my choice of a 350 v-8 would not work. If the goal is to put a carb on a Corvair flight engine, no one can argue that my choice to use a MA3-spa will not work. They might say it was expensive, (valid, but not in the big picture) hard to find (not valid, just call Russ) or less efficient that EFI (not valid, see my testing), but no one can even begin to say that this carb is not reliable. It works and does this task with stone reliability, end of story.


Above, this side of the carb shows the accelerator pump, and the bronze mixture control arm. the orange plug it covering the threaded fuel inlet port which an AN fitting goes in. Just to beat a dead horse, let me point out that Bing carbs on Rotaxes just have barbed slip on fittings for rubber hose and hose clamps for fuel inlets.

The intake in the background is for our Wagabond. It is stainless, just like our others, but I elected to have it powder coated. It has a longer, one of a kind up pipe between the carb flange and the main pipe, on production manifolds this is about 1/2 that length. The small tube was for a primer line when the plane  was equipped with a Stromberg carb. Going to an MA3, I have deleted the primer system. I will just have to find a plug to fill the hole….or maybe just screw a NOS nitrous fogger nozzle into it….-ww.

2 Replies to “MA3-spa carb pictures, Wagabond notes.”

  1. William.

    Is there any news about mods or improvements for the Wagabond?



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