912 overheating after maintenance

It may not be the issue. I was just covering all bases. Seems when you leave one stone unturned that's the one you should have looked under.

I got ahold of the mechanic (Mike at the Boundary Bay Airport) that did the engine work.

Mechanics feedback:

1. Change spark plugs. Get the number off the old plug. DCPR8E, he put these in he thinks. 7E was what it originally came with. The plug might be too hot. 

2. Needle position usually the 2nd from the bottom, Find out where its at. He doesn’t remember changing it.

3. Radiator might have an air bubble. Look at coolant or oil system. Oil cooler could need a flush.

4. he wanted me to pull the front two spark plugs and see if they had brown marks on them or if I could tell if they were running lean.

5. muffler, he thinks it would be unlikely. 

There isn’t a Rotax A&P at my airport, and my A&P friend said not to fly it at a 250 degree oil temp.

In a bit of a pickle here…

Ramblings;

1- Unlikely to be the cause however good the check that Rotax approved plugs are fitted (odd that this would be in doubt).

2- Changing carburettor settings is a significant decision (owner should be in on decision) - cant believe he is leaving this Q open - either he did or he didn't.

3-  Air in either coolant/oil system should be removed by Rotax approved methodology. This is not a flush, which is to remove a build up of "sludge". I don't use AvGas, so if you do, my comment, may not  be relevant.

4 - Its common/normal for front plugs to be dark/black - got nothing to do with rich/lean setting. If setting overly lean (back to #2) plugs could be lighter colour than usual.

5- I agree although if muffler overly restrictive may have an impact on engine temps

Nick,
This might be a bit “out of the box”, but I think the Rotax powered DA20 had cylinders 1&2 exhaust headers wrapped from the factory??  And, an A&P would have to remove the wrap for annual inspection of the headers and maybe to replace the muffler.  Were your headers wrapped, and if so, are they still? 

Hi Jeff,

The front two cylinders 1&2 are still wrapped.

The mechanic said we can remove the wrap. They have been wrapped for the last 5 years atleast. 

Will these high temps harm the engine? It looks like I’ll have to fly the plane at least 1 hr to a rotax mechanic.