Hard Start of First Try

After speaking briefly with a Rotax mechanic down in Sebring, FL, he suggested I try using a hair drier (not a heat gun) on the coils to heat them up before I try the first start of the day (when I would KNOW it would start rough).  After having pulled the data from the G3X, I knew the problem was in the number 1 cylinder. So I heated up coils 1 and 2 (as each fires one plug in #1).  Perfect start. Those perfect starts lasted for several 'first start' attempts until the airplane sat for a couple weeks. Then yesterday another rough start. So rough in fact it quit and then on the subsequent start, it fired right up as normal.  So, my next time out will be to hit ONE coil with the hair dryer and see what I get on the first start of the day. Maybe I can whittle this down to a problem with one coil or the other. (Also, I can't really understand how heat is really making a difference anyway. I live in Florida...I figure the coils are always as hot as I am at least)

Wrapping a one gallon bag of ice around them for about 30 minutes also works and if this does work then you need to replace your ignition modules.  Don't need much ice in the bag because you want it kind of flat to wrap around the edges too. This has always worked for many Rotax owners.

Okay, so, basically, if changing the temperature of the ignition module (either hot or cold) solves the problem then that is the bad module and a change will solve it. I'll try it. Thanks, Roger!

If someone on your field has a Rotax engine like yours you could also ask to borrow theirs for a test and that again would prove it. That said the ice trick has always worked.