ORIGINAL: skrilla
ORIGINAL: bigdogkanicsar
<div id=''TixyyLink'' style=''border-bottom: medium none; text-align: left; border-left: medium none; background-color: transparent; color: #000000; overflow: hidden; border-top: medium none; border-right: medium none; text-decoration: none''>ok, you are right. how ever i did have to richen to keep it runnin i do remember that much. now it may have been that i was tryin to run in 115 degrees and 85% humidity and the fuel wouldn't burn. all i know is the engine was hot and i ran it richer to cool it off, this was twelve years ago. to be honest i pretty much listen to the engine to hear what it's doin' and go from there. so, you're right i had it backwards.
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If the outside air temperature was 115°, then that is clearly the sole reason you had to richen it. On warmer days we sometimes have to over-richen the mixture to keep the engine temperature down. However, with high humidity, there is less available oxygen in the intake charge, so to adjust for that you need to lean the mixture. Unfortunately, high air temperature and high humidity often occur at the same time. So while very high temperature outside forces you to richen some, high humidity forces you to lean some, creating a pretty tight tuning window. It's pretty much a double whammy. You want to keep it cool but you also want to it to run good. This is one of the reasons I am not a big fan of running on very warm humid days, not to mention standing outside sweating my arse off. We only have a week or two of that (90+ degrees, 80%+ humidity) here in central Indiana, if at all.
yeah ,it's not often that you find cool days with high humidity. for the most i tune till it runs right and let her rip, and don't think about humidity. the OP mentioned it and i started thinking about va. and how2 humid it was there in the summer.