My Zenith has a choke. No need for a primer. The 2180 VW starts immediately in any ambient temperature. There is no drama for hot engine starts; with the 0-degree advance electronic ignition at zero RPM and with choke off, starts are immediate. Max advance on the ignition is 29 degrees. My 2180 is rated at 76 hp. The Zenith has an adjustable main jet also used as a mixture control. I rigged a VW speedometer cable to adjust the mixture from the cockpit. The gland nut on the main jet needle needs to be tight or the needle shaft will leak. If the gland nut is tight, the needle shaft cannot be turned. I have set the mixture to 13.6 for best power at wide open throttle on this engine using a panel mount O2 sensor mixture meter and leave it there. I am still looking for a better mixture control. (Best efficiency for cruise is 14.7) Looks like I will have to get a different carb that has a practical mixture control. That new carb will probably not have a choke; so, would need a primer system. Along with that would come the hot start drama.
Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA ------------------------------------------------------------------------------ > From the reading and talking to others it would seem that several carbs are an option and as such I would ask that anyone who has tested them give me and the list some feedback as to the experience good or bad with the following list or any others that have been tested. Marvel MA3-SPA Stromberg NAS-3 Ellison EFS-3A Zenith 268 Rotec #3 Regards Stan