Purge engine at oil change

[jnmeade]

Thanks, Piper J3, here are some excerpts from the Rotax Owners post by Lee. Go to the cited reference to see the entire post, or Roger (Sink) can repost if he wants to.

"The only oil listed was Valvoline at 25 hrs. back in 2009. No other entries in the books other than each year it said it was found to be in a safe condition for operation. There were many things wrong here and this was just one of them. So the oil may be as old as 6 years, no one knows and the oil maybe auto full synthetic. It will not suspend the lead and isn't a motorcycle oil that will protect the gearbox....

Even with the years in age the lead fell out of solution in 58 hrs."

This situation reminds me of the aphorism, ""Great cases like hard cases make bad law" declared Justice Oliver Wendell Holmes, Jr. "

That is to say, there is really little to be learned from a case where an owner and mechanic so neglected and abused the system. It really says nothing about what most of us will encounter as owners, operators or mechanics when it comes to 100LL and changing the oil every 25 or 40 or 50 hours.

Let's suppose you took a 4 week a tour of the U.S covering 50 hours and used 100LL all the way. Would the oil look like that in the video Lee posted? I doubt it, but that is the question. Using the above example only speaks to a particular and extreme case of abuse and only tells me to not let my engine sit for 8 years.

It would be interesting to see what engine operations were conducted over the 7 year span, if any.

It would be interesting to see the credentials of the mechanic - was this an E-AB owner? A LSMR-A? An A&P?

This is kind of like showing a picture of a baby that was tossed off a 5 story building as a reason to not toss your baby to the ceiling and catch it in your living room.

[Jetguy]

Just cleaned my oil tank for the first time in 788 hours. I've run 98% unleaded auto fuel. Looked great with a small amount of sludge in the very bottom of the tank. Won't be doing it again any time soon.

[Sink]

Hi John,

Nice job.

If using unleaded fuel and doing the appropriate oil changes then tanks tend to remain quite clean. Using 100LL all the time and regular extended oil change intervals can certainly cause build up down in the bottom and on the screen. Yours looks like I would expect with unleaded fuel use and good maint. practices.

[RFSchaller]

John,

Since you are burning auto gas are you using a 50 hr oil change interval? I'm interested because that's the interval I use and I burn Auto gas >90% of the time.

Rich

[Jetguy]

Originally Posted by RFSchaller

John,

Since you are burning auto gas are you using a 50 hr oil change interval? I'm interested because that's the interval I use and I burn Auto gas >90% of the time.

Rich

Yes! After watching those youtube videos I got motivated to clean the tank.
Now that I've done it all the mystery has gone out of the procedure. I did order a new o-ring that goes around the rim since mine hasent be done for some time. that O-ring is a little expensive, $32.00. I will probably do it every 200 hrs or so. I like a clean engine.

[rvbuilder2002]

The tank o-ring is reusable and doesn't need to be replaced every time the top of the tank is removed.

[ben barron]

Burping then draining....to change my oil and filter I am finding I need only 2.6L of oil to get to the mid point of the dip stick. Is this common?

[rvbuilder2002]

Originally Posted by ben barron

Burping then draining....to change my oil and filter I am finding I need only 2.6L of oil to get to the mid point of the dip stick. Is this common?

Yes

Burping doesn't drain the entire oil circuit. there is still some oil in the oil cooler and pick-up hose.

[PilotBrent]

Always appreciate when others post pictures on here so I'll offer a couple as I wrap up my annual. First is the magnetic plug which was last removed about 120 hours ago. (change oil about every 35-40 hours with minimal leaded fuel use) I confess that I'm lazy and don't remove the magnetic plug at every oil change. (Plug is safety wired to a point below the oil filter so to access it the lower cowl needs to be removed.) I do have the oil analyzed and open the filter so I didn't suspect any problems. Looks fairly clean to me considering the hours.



These are my spark plugs. First picture is at last year's annual when they had just under 100 hours on them. Engine was running very smoothly. Since they looked clean, I just checked gaps and reinstalled. Second picture are the same plugs now with 227 total hours on them. Several of them had gaps that were out of tolerance per ROTAX manual. Engine was still running very smoothly nonetheless. Yes they are cheap and will likely replace every year going forward.

[bobnoffs]

amazing videos.aviation tech. sure has come leaps and bounds in 80 yrs.