I don't believe the MA3 is a tractor carb. Marvel-Schebler makes a bunch of carbs for tractors that look similar but what makes it an MA3 is the type of mixture control it has. For instance, there are 4 "styles" of "main jet" controls, in their manuals, they call them "power adjustments". There is a fixed jet, and 3 different types of adjustable jets. Two of them are on the top of the bowl and the other is on the bottom of the bowl. The one on the bottom of the bowl is exactly like the Zenith carb with the "tee" handle adjustment. The other one, used on the tractor models, is a knurled knob on top of the bowl. The last type is only on the MA3, 4, 5 etc and was made only (from all I have researched) for aircraft application.
The differences between the MA3(and up) is that the MA series employs a mechanism that turns the short 90deg (less than 180) lever action into linear motion on the needle. So instead of needing to turn the needle 4 to 6 turns to go from full rich to closed, the mechanism in the MA series does it in less than one turn. It's more like a valve. I think you'll be disappointed if you buy a carb for a Ford 8N or 9N and try to put it on your plane and expect to have mixture control like what you are used to in the air. Now, if you don't care to have the aircraft style mixture control, then knock your self out. Get one intended for the Ford 8N or 9N and you're golden. I think another difference is the MA series is Aluminum and the rest are some other ferrous casting...or if you get a really old one, brass. my 2 centavos On Mon, Nov 26, 2012 at 7:40 AM, Larry&Sallie Flesner <fles...@frontier.com>wrote: > > > Has anyone checked out the carb's at (google) "marvel ma3 tractor > carburetor" ? The price sure looks good. I'm running an MA-3A (I > think that is the number) on my 0-200 and haven't touched it since > doing a rebuild and installing it 450+ hours ago. I recall mine > having the metal float and the single piece verturi AD's with now problems. > > Larry Flesner > > > _______________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html >
