SonexBuilders.net

Anybody have any experience using a Zenith Carb on their AeroVee engine? Great Plains recommends them for their VW conversions. Thanks

Scott Casler at Hummel engines also uses the Zenith Carb.Keep in mind you will have to add carb heat.

I have always been curious about the Zenith carb. Does it work well, how does the mixture work, and so on. Does anybody have one on a Sonex?

Mike53 wrote:Scott Casler at Hummel engines also uses the Zenith Carb.Keep in mind you will have to add carb heat.

From an EAA Experimenter article titled "Four VW Powerplants" we get:

The Zenith carburetor is simple and inexpensive and features a cable-controlled choke, low-speed idle bleed screw, mid-to-high-range fully cockpit-adjustable mixture control, idle adjustment screw, replacement venturis, and float bowl vent.

Complete article here:

http://www.eaa.ca/experimenter/articles/2010-02_powerplants.asp

Dale
N319WF

My partner and I are in the process of installing a Zenith on our Sonex that has a Great Plains engine. We had the Aerovee carburetor, but had trouble adjusting the mixture. We bought the Zenith on line from an individual, so didn't have a lot of information about it. All we knew was that the bore of the carb was the same as the Aerovee. Since the connection was different from the Aerovee, we had to make an adapter. Since the Zeinith is taller than the Aerovee, we had to shorten the intake runner tube to make room under the cowling. Then we had to make an adapter for the throttle connection. On the initial startup with the Zenith, we had to prime it to get the engine to start. The engine ran fine and it was easy to adjust the high speed mixture. The engine developed full rated RPM with the plane at rest. We found the mixture was going too lean at idle, and were unable to richen it enough using the low speed jet to enable a smooth idle much below 1500 rpm. The carb is equiped with a 38 mm venturi, and we have been advised that a smaller venturi would enable us to richen the idle mixture. Zenith made various sizes of venturis and it is easy to remove it, but so far we have not been able to locate a suppy source. If anybody knows one, we would appreciate knowing it. We are looking for a 32 mm venturi.

I would talk to Scott Casler at Hummel engines (520) 723-5283 ( 520) 518-4708 Mobile for the best advice.I too have a Zenith carb supplied with my Hummel engine.
Cheers,
Mike