I would love to see a video going into more detail on this, and in particular the differences between the 912ULS and 912iS dog clutch. The former has 30(?) angle, the latter 0 degrees - which angles?
I have a fuel injected 912 Sport with 500 hours. Im getting a lot of vibration when I reduce power in the 4k rpm range. Im betting it’s worn dog gears. Have an Eprop on order.
That looks more like a running design change than a wear issue. You can still see the edge chamfer on both "worn" parts which would suggest the ramps have not worn much at all.
The dog clutch is Totally independent of the slipper clutch. Just avoid heavy Constant speed props and heavy props in general and your gearbox is gonna last so much longer. Another common fault is the crankshaft gear retaining nut comes loose. My recommendation is use a eprop and save your gearbox
Correct me if I'm wrong, but doesn't that dog setup also tension the drive's clutches? Seems counterintuitive that the dogs should tighten the slip clutch in the event of a prop strike and cause more crankshaft damage?
@@danielaustralia5820 Thanks. I was really wondering if people generally found that if one dog needed replacing then both need replacing. I haven't pulled the gearbox off yet, just trying to anticipate and order in likely parts
The problem I think only surfaced when they went to 100 hp and had to use high compression and bigger pistons . So you get more harmonics like they had to change gearbox on the big 2 strokes engines .
@@danielaustralia5820 Their concept ideas go against common sense. The whole world had develop, tested and conformed wonderful projects and ideas. But, rotax has better ones! LOL. This reduction box.... When this engine starts and stop you hear that sharp bang noise of metal to metal. The tiny little engine is begging for lower compression rate! LOL. No! High compression rate, high RPM, tons of plastic around the little "furnace" heating up and cooling down...What about the price? In some cases the same or more than a reliable Lycoming. Oh, it's more efficient... Really? every 500 hours puling out the reduction box to inspect...On and On and On...
@@ele4853 Rotax parts and parts and Pricing away of the top but however there’s not a lot else you can buy. People think the gearbox maybe more maintenance but you end up with a lighter engine all up and you don’t have to completely strip it when ever props Strike .
Agree, but Cant get the power to weight ratio with a lycoming. I wish we could. I find the Rotax buzz grating after a few hours flying behind it. But 118 knots at 4.5 gallons an hour makes it worth it. BTW I had a catastrophic Rotax engine failure on my last plane and almost died. Mechanic left an oil line loose at annual. N121YT if you want to look up the report.
@@Bill3558 My take on aviation engines is reliability, not efficiency. Whoever buys and engine like Rotax averaging 30K, gas should not be an issue. Now, when it comes to how long these engine are going to last without a problem, there's no comparison between Lycoming and Rotax. There is data out there for anyone to see. My life if more important then price of gas. Rotax is like microslop. They invest heavily on marketing and the customer pays for "development". Terrible approach when comes to aviation.
