Something new and something old for the Rotax engine

[roger lee]

New:

Rotax has put some language in place in their manuals because some products like sealers aren't readily accessible in the US or other countries. So now you can use a suitable and comparable replacement or more specifically "Technical Equivalent", but you do accept the responsibility for getting the correct substitute.
Rotax used to call for Loctite 5910 for sealing the gearbox and in a few other places. The problem was it only came in a 300ml tube which may last most people a lifetime and then get handed down to someone else.
The US replacement is Loctite 598 and can be purchased from several different sources and in small quantities.


Old:
There have been many numbers thrown around for the Rotax starting required rpm. We don't have magnetos we have trigger coils. In order for these to get excited and fire current to the plugs we need a minimum of 225-250 engine rpm which translates to 92-103 rpm using our 2.43:1 gearbox ratio. Now if your battery is weak and you only get 85 prop rpm or less it won't start. You can not tell the difference looking at the prop or listening between the 93 to 85. So if your aircraft doesn't start you need to use a newer battery or jump it to rule out the possibility of a poor battery.

We have 5 trigger coils. 4 for our needed amps/voltage and one for the tach signal.

[drseti]

Rotax used to call for Loctite 5910 for sealing the gearbox

I had a problem with oil seepage from the gearbox to crankcase interface in my 2006 912ULS. Seems that Rotax used some other sealant at the factory for a brief time. I learned this when I took the Rotax Maintenance Level course from CPS. Last year, when I pulled the gearbox for its 600 hour inspection/maintenance, I buffed both mating surfaces with aluminum oxide abrasive, cleaned them well, and then ran a bead of that expensive Loctite 5910. Result: absolutely no oil leakage. Even if the rest of that 300 ml tube goes to waste, it was worth it!