user 15974
J3C46ChrisM
- Joined
- Aug 27, 2018
- Messages
- 245
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- 76
I have a 1946 J3-C with a Continental 85-12 engine and a Marvel Schebler (sp?) carb, which is wired for full rich 100% of the time. The carb heat notation on the knob says "Carburetor Air". Yesterday after an hour of flying in the pattern, and using the carb heat for five previous landings with no problem, the carb heat stuck in the "on" (out) position. This is the second time it has happened to me in the 1-1/2 years I have owned the Cub. The first time I took the cowling off and used WD-40 applied to the spiral wound casing for the carb heat line, which worked for a while. I presume that WD-40 simply evaporates when the engine gets hot enough. Removing the cowling on my J-3 is a PITA, due to the tightness of the pins that hold the cowling on, so I want to minimize removing the cowling if at all possible. I actually have three questions -
1) Do I really need to use carb heat for every landing? In other Piper aircraft with Continental engines that I have flown, some of the POH's say only to use it to clear carb ice.
2) Is there some sort of lubricant for the carb heat line that would be better than WD-40, which seems to soak through the spiral winding line casing pretty well?
3) Would it be better to simply replace the carb heat and casing with a new one at the next annual (next month)?
I should also note that when it stuck open, I had forgotten to push the knob in prior to takeoff, and the reduction in engine performance was minimal, so I simply went around, landed and put the plane away for the night (I was on my last landing of the day anyway). This leads me to wonder how effective the carb heat is anyway.
1) Do I really need to use carb heat for every landing? In other Piper aircraft with Continental engines that I have flown, some of the POH's say only to use it to clear carb ice.
2) Is there some sort of lubricant for the carb heat line that would be better than WD-40, which seems to soak through the spiral winding line casing pretty well?
3) Would it be better to simply replace the carb heat and casing with a new one at the next annual (next month)?
I should also note that when it stuck open, I had forgotten to push the knob in prior to takeoff, and the reduction in engine performance was minimal, so I simply went around, landed and put the plane away for the night (I was on my last landing of the day anyway). This leads me to wonder how effective the carb heat is anyway.
