Hooooo Kaaaay, This can turn into a dissertation, but I thought it was interesting, so maybe you will, too. This is what I believe I have learned.
1. The Ercoupe with Stromberg carb needed a primer for starting because the Stromberg has no accelerator pump. (The Marvel carb does, in contrast, have an accelerator pump.) 2. On aircraft having a carb that includes an accelerator pump, pumping the throttle is a popular but dangerous way to start an engine because it puts excess fuel in the carb where it can cause an engine fire. The safer way to do it on, for example, a Cessna-152 is to use the primer because the primer puts fuel DIRECTLY INTO A CYLINDER, thereby bypassing the carb. 3. HOWEVER, the Coupe primer does NOT put fuel in the cylinder. It squirts it into the carb, just like the accelerator pump. (I learned this when I paid to have my primer, which had been cut and crimped, re-installed. They did this when they replaced the Stromberg carb with a Marvel carb. But, I felt it was dangerous so I undid the primer change. That's when I learned that the primer goes to the carb, not the cylinder, just like the accelerator pump on the throttle.) 4. SO, on a Coupe use of the primer and use of the carb accelerator pump are both hazardous. 5. I am going to try using the primer ONLY while the prop is turning, as I see is advised by one member. Anybody see any errors in this summary? Dave Winters To: [email protected] From: [email protected] Date: Thu, 5 Aug 2010 13:20:14 +0000 Subject: [ercoupe-tech] How to start an Ercoupe At Oshkosh during the Ercoupe maintenance session the best method of starting a Coupe was described as: slow back when pulling primer out; push in more rapidly; slow back again; engage starter and push in primer simultaneously. Works every time so they say (I haven't tried it yet). I had been told that pushing in the throttle once would help but the consensus at Oshkosh was that it would be useless. Don't disagree but can anyone tell me what using the throttle during the start does? Mac McMahon N94184 VKX Friendly, MD
