My 1999 vintage Rotax 912 100hp (without soft start) is difficult to get started whenever the temps drop below 60 degrees F which is most of the time where I live.
I have installed the latest generation 912 flywheel which supposedly retards the ignition even more at start up and a new battery and starter.
My next step is to convert to the latest generation Rotax ignition modules with the built in soft start feature.
My definition of hard to start is when after going thru the starting routine, it does not immediately start and idle like the car I drive to the airport.
I feel sorry for the starter when it repeatedly acts like it is pushing against a wall and wonder when the engine will need to be removed to replace the Sprague clutch from the abuse.

Everyone but me has already figured this out, but I recently found that preheating is amazing.

I have known about the Reiff 912 phone activated preheat systems for years but hesitated because the system requires several hours to get up to temperature and I never know when I plan to fly.
I thought that it was hard on the engine to leave the heat on full time but I learned that the condensation that forms from cycling the heat on and off is what damages the internals.
Then I rationalized that if I lived in southern California where for several months of the year the night time temps do not drop below 80, how can it hurt the engine to leave the pre heat on full time?
Hal Stockman from Rotax 912 Big Bore Kits, suggested I go to Napa auto parts and pick up some 2" x 5" self adhesive 50 watt engine block heater strips.
I found these strips on Amazon for $18 each and installed 2 on the bottom of the 912 engine case and one on the oil tank and found a thick moving blanket to drape over the cowl to help retain the heat.
I came back the next day and was shocked how warm the cowl felt.
The oil temp gauge indicated 112 degrees and it started on a near freezing day like my car does.
I disconnected one of the case heaters and the next day the oil temp guage indicated 96 degrees before start up with the same immediate easy on the starter and Sprague start up.
This still leaves a starting issue when away from home in the cold mornings of the Idaho Backcountry but that is only a few days a year.

I would be interested if there are any comments regarding leaving the preheat on full time other than constant power usage?

Has anyone converted to the Rotax modules with the built in soft start and noticed an improvement when starting the high compression 912's with or without a big bore kit?

Thanks
Herman