Do a good ROTAX pre-install inspection

One thing that surprised me when I installed my ROTAX 3 years ago was that not all the items designed to be safety wired were in fact wired, and my manifold pressure hose did not have a hose clamp where it attached to the balance tube. It seemed tight so I left it as is. Today (after 250 hours on the tach) while fixing an EGT probe connector I found the sensor hose had slipped off the balance tube nipple (which may explain some performance degradation).

Pretty simple stuff and I feel a little naive, but I wanted to post because some builders might make the same mistake I did in assuming the factory would have every safety wire and clamp in place. Be a skeptic!

As I recall the plans call out for zip tie it to the over head coolant bottle supply line only, I think for flying 12's when check the carbs for every 25 hrs check something etc to be on safe side

There's also the mag plug, which should be safety wired. Some also put a clamp on the oil filter and safety wire that, although I've been told it's not necessary if it has been properly installed.

I have 400 hours on my 912ULS powered CT and the oil filter has never budged. I don't know of any that have.

An engine from Rota needs to have the oil magnetic plug and the oil pressure regulator plug safety wired. It does not come from Rotax that way and most aircraft MFG's don't do it. If the oil filter is installed properly it WILL not come off. The only ones to have ever done that was because it wasn't installed properly. If you can take it off with just your hand it may be too loose.

RFSchaller said:

One thing that surprised me when I installed my ROTAX 3 years ago was that not all the items designed to be safety wired were in fact wired, and my manifold pressure hose did not have a hose clamp where it attached to the balance tube. It seemed tight so I left it as is. Today (after 250 hours on the tach) while fixing an EGT probe connector I found the sensor hose had slipped off the balance tube nipple (which may explain some performance degradation).

Pretty simple stuff and I feel a little naive, but I wanted to post because some builders might make the same mistake I did in assuming the factory would have every safety wire and clamp in place. Be a skeptic!

Click to expand...

The KAI says that did not have to be wired if I recall correctly, I remember throwing a good tie wrap on it anyway. One of my AP buddies suggested pretending I was engine vibrating for 1000 hours and anything near it that can become loose should be wired or secured with a clamp, and anything that rubs needs to protected against rubbing.

Hoses, zip ties and safety wire

I'm just wrapping up my first annual. Just prior I completed several of the fuel tank upgrades, canopy latch switch install, ADAHRS stiffener, misc other service bulletins so its taken several weeks. (I do need to move my annual schedule to a warmer month)

On advise from DAR last year I added multiple zip ties and RTV sealant in and around the Rotax coolant, fuel and oil hoses. While Van's had identified a few of these spots in previous updates he had seen and maintained a earlier built 12 and was familiar of a few places that has show some wear from vibration. While I removed several of the zip ties to complete the inspection/check fasteners etc..., I could not find any signs of hose wear. Only minor engine compartment issue has been the lower right cowl hinge pin which keeps riding up due to engine vibration. Added safety wire to hold it to the firewall stiffener. There are a lot hoses on the Rotax and I'd recommend securing them in as many places as possible. Zip ties/RTV are cheap.

Funny about that "lower right cowl hinge pin" vibrating up -- mine does the exact same thing. All the other pins seem happy to remain in place. I added a little clip at the top of the "lower right cowl hinge pin" to keep it properly corralled. Must be some unique vibe thing going on down there!

Lower right cowl pin

Here is one more idea to secure the lower right cowl pin from floating up. Make a new pin with the top bent as shown so it can be rotated and hooked under the bottom of the oil tank bracket:




If the top right cowl pin wants to vibrate up, just make it longer. Then once the top cowl is on it can't come up:


P.S. I may have posted these pics before in another thread, if so please forgive the duplication.

I have no idea why, but my upper and lower cowl pins stay put.

Missed your previous post on this Tony

Great idea, will be doing that myself. A lot easier than trying to install safety wire in that tight space every time I reinstall the lower cowl.
Brent.