Oil line plug caps

You don't  need any caps if you remove the oil lines off the tank. When you normally drain oil the oil in the fittings at the top drian too. If you remove a line just tuck it under a hose or wire to keep it above the tank level. No more oil will come out than a normal oil change. When you unscrew the tank fitting and lift it off you most likely won't see more than a couple drops of oil. Just remember to keep both fittings above the tank top so no oil drains from the hoses. If you allow the hoses to drop down and completely drain then yes you would need to do a purge. The key here is don't let any oil drain from the hoses.

p.s.

If you want you can go to the hardware store and buy a couple of rubber plugs to stick in the fittings when you remove them. I use rubber plugs when I do a 5 year hose change to keep from making an oily mess on the floor.

Roger you are right on except for one thing. The oil line coming from the bottom of the engine can be left dangling as low as possible to help drain all the oil from the crankcase; in fact it is a good thing to do this to get as complete an oil change as possible. Doing this will definitely NOT require a purge procedure. The other oil line, that goes OUT to the oil pump must be kept tied up above the oil tank level as you say, or else a purge will be required. I have been doing it this way for 11 years with no problems. I remove and clean the oil tank about every 2nd or 3rd oil change.

Hi James,

Out of curiosity;

"....in fact it is a good thing to do this to get as complete an oil change as possible."

 # Other than satisfaction in a job well done, why do you think that it's important/beneficial to remove the last few drops of oil?

"I remove and clean the oil tank about every 2nd or 3rd oil change"

 # How much residue do you remove, from the oil tank, at these intervals?

 # What is your oil change interval?

 # What oil are you using?

😈

Sean, Its not really important, but I do get quite a bit more than a few drops out of that dangling oil line.

I change oil every 50 hours, using Aeroshell Sport Plus 4. Normally there is no residue, however if I have been on some x-country flights where I am forced to burn 100LL it is surprising how much lead scum I wipe out of the oil tank. I vary the intervals of cleaning the tank based on how much or how little 100LL was burned. When I clean the tank, I usually don't remove the whole tank, just the top and all the innards. 

Thanks James,

When I asked the above questions, I hadnt thought of AvGas/lead as a possible reason for your frequent tank cleaning.

I don't use any AvGas, however, like you I have opted for 50 hr oil (not filter) changes rather than the Rotax 100 hr allowable. Just makes me feel good.😈