Per the Rotax instructions, the oil system must be purged any time the oil suction connections are opened. Running through the process after re-installing the engine on my Merlin GT. WARNING! I ain't no A&P - Watch at your own risk!!!
Jim, does the engine have to be purged prior to each start? I'm about to purchase a Titan with 912 and find your video very useful. If you are on a cross country, do you have to purge after every shutdown? Thanks!
Oh, heck no! That would be a good reason to not buy a Rotax!!! Some sources advocate purging the system after each oil change, but Rotax only tells you to do the purge after you open one of the oil lines on the suction side of the oil pump. As far as the "Burp" or "gurgle" is concerned -it is somewhat installation dependent, but I only do that if the oil level on the dipstick appears to be low. If the level on the dipstick is OK, pushing the oil out of the crankcase will only make it go up. You just don't want to add oil and overfill because some is "hiding" in the crankcase. So burp and check before you add.
Wait. Don't the instructions say to measure the gap while holding the rocker in? A hammer in the shoulder while pushing with the handle frees the hands to run the feeler gauge for that 0.5 mm. Thanks for making these videos. I just did my first oil change yesterday and your input has been a most helpful contrast to the service instructions.
From si-916i-003-r1... "3 Push down the rocker arm on the push-rod side with a force (F) of around 70 N (15.74 lb-force) for about 3 seconds. You can using a belt tester, for example, to check approximately how much force is being exerted. Repeat on other rocker arms. 4 Check distance between rocker arm and valve contact surface. Max. allowable distance 0.5 mm (0.02 in.)." Which suggests to me that you can do the two steps sequentially. If there is air in the lifter, I would think it would collapse a bit and not spring back when you push.
I guess I got the idea from this guy: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DFfxHbaU_Bs.html He also says to use only the rotax filter, but I used a Wix 51083.
I hate to ask this question, but can the oil system be purged without disconnecting the return line and pressurizing the system with a compressor. Thanks!
Per this service instruction legacy.rotaxowner.com/si_tb_info/serviceinfo/si-916i-003-r1.pdf the compressed air is optional. But I suspect it's going to take quite a bit more prop flipping...
Thanks. I've heard about the compressed air being optional, but I was looking for the reason on why you can't just keep turning the prop until oil pressure shows up and just leave the line connected.
Instead of removing the plugs and hand spinning the prop, why not leave the plugs in and briefly use the starter? Ignition off of course. FWIW: I've got over 2850 hrs TT on my 912, and have had the oil system "open" several times, and have never gone to the extent of what you detail here, just saying. NOT that you are wrong or anything, but Rotax goes a bit overboard in many of their procedures and recommendations, replacing all the rubber components every 600 hrs. is a prime example. =Point being, after all you did, the lifters were fine, correct?
Yea, Rotax does seem to go over the top sometimes, but it cost me nothing but a bit of time to pretty much follow the published procedure so... (I don't do this for an oil change btw.) Starter probably would work to spin, but with the plugs in you will push oil out the return so you would want some kind of "catch" system. And, yes, lifters have been fine every time I have done this. (They also love their (expensive) special tools... :-( )
@@LightAndSportyGuy Thanks for the reasoned response! I LOVE the fact Rotax is so anal in their maintenance recommendations, and for sure don't fault anyone who follows all of them. I have to be careful when I tout the number of my trouble free hours, using non Rotax oil filters (Donaldson) and other "reckless" practices, as I certainly don't want to encourage others to do so. I was dragged kicking and screaming into the Rotax camp, (1300 hrs on a Soob conversion before, also trouble free, but heavy) but I now love the engine, it's especially fun to get into a discussion with a legacy engine pilot who disses the 912, few if any can match the trouble free run I've had, not to mention the fuel economy!
