I have a 1945 J3 C-90 8F with no electric and no mixture control. After getting an STC to run MoGas, I've flown about 12 hours. I have a minor fuel leak on some fittings so I switched back to 100LL for the last few hours to spare my mechanic the smell of MoGas. Not sure if there is cause and effect, but the stock Stormberg carb started coughing and almost forced me to land off field. I nursed it back to life and was able to land.
Back at the shop, I cleaned the spark plugs and did a mag check. Roughness between 1200 and 1800 is horrible. With carb heat on, I was able to get it up to higher RPM but mag check is rough on both sides. We narrowed it down to a gas problem rather than sparks or mags.
So.... I am thinking about putting on a new Marvel Schebler carb with mixture control. Any suggestions? What is the best way to add the mixture control system? I don't want to change the plane too much from stock by adding knobs, but I fly at a lot of higher altitude airports and would like the ability to lean both for economy and to spare myself of fouled plugs. Also, I need to get over a few passes, so getting the most the engine has to offer seems reasonable. I mostly fly solo, so I am flying from the back so I am not sure a not on the front will be convenient.
My concern is that this cub currently pretty much stock and unadulterated. The airframe has less than 600 hours and the C-90 installed in 1956 has only 350 hours or so.
This is my first post since buying the cub. I love flying it. It has been a true joy. Any input welcome. Stromberg vs. Marvel to lean or not to lean and AvGas vs. MoGas. I am a newb and willing to learn. So give me the uncensored share.
Back at the shop, I cleaned the spark plugs and did a mag check. Roughness between 1200 and 1800 is horrible. With carb heat on, I was able to get it up to higher RPM but mag check is rough on both sides. We narrowed it down to a gas problem rather than sparks or mags.
So.... I am thinking about putting on a new Marvel Schebler carb with mixture control. Any suggestions? What is the best way to add the mixture control system? I don't want to change the plane too much from stock by adding knobs, but I fly at a lot of higher altitude airports and would like the ability to lean both for economy and to spare myself of fouled plugs. Also, I need to get over a few passes, so getting the most the engine has to offer seems reasonable. I mostly fly solo, so I am flying from the back so I am not sure a not on the front will be convenient.
My concern is that this cub currently pretty much stock and unadulterated. The airframe has less than 600 hours and the C-90 installed in 1956 has only 350 hours or so.
This is my first post since buying the cub. I love flying it. It has been a true joy. Any input welcome. Stromberg vs. Marvel to lean or not to lean and AvGas vs. MoGas. I am a newb and willing to learn. So give me the uncensored share.
