Wow, 'tis the season to talk carb heat...just had a long thread about this on another list in conjunction with to lean or not to lean.
Anyway, I've got a C-90 with the Marvel my understanding of which is that it is especially prone to icing because of where it is mounted. Apparently, the same carbs are not as ice-prone in the Lycomings because it is mounted nearer heat-producing parts of the engines. Evidently, the Continentals were designed when there were still considerable issues with fuel causing vapor lock, so they opted for a conservative design which tends to keep things cool hence the icing tendency. On fields of a half-mile or less, I pull carb heat right at the beginning of downwind and leave it on, even in the summer because I live in a place that tends to be humid. My understanding is that if you're below 72F at your pattern altitude there's still a chance for ice. I've not had problems with go-'rounds as long as I quickly push in the carb heat after applying full power. That might be a by-product of my engine/prop combo, though. In terms of running rough, well, every other instruction in the A2 manual is "...unless rough, then lean" so to me it seems like there are a bunch of things to consider if it sounds rough like if it might be running a bit rich. Leslie 3B9 ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com
<<attachment: winmail.dat>>
