Online Community of Zenith Builders and Flyers
Did a long cross-country on Saturday. It was a 300NM flight, taking 5 hours of time (including touch and gos, ect). 19.5 gallons burned.
Landed at four airports that were new to me and to the 7-Oh-Fun.
That leaves only 11 public airports in Western Washington that I have not landed the 701 at.
So here are the facts:
1) My engine is back together and the plane is flying again
2) The only parts replaced were CHT probes, seals, gaskets and overflow bottle.
3) Compression is 86,86,86,85
4) Full root cause is still not fully known.
Between myself and my Rotax guru A&P we have a probable cause:
1) A near gross load reduced climb & cooling performance allowing for increases in coolant and oil temps.
We are still trying to figure why exactly all the coolant came out. The best hypothesis is an airlock developed in the system and forced the coolant out.
That still leaves us wondering why the airlock started in the first place.
Once piece of the puzzle has been figured out, which sadly creates a new question. The bottle failed due to exhaust heat. We were seeing EGTs close to the yellow\warning zone before the failure. The portion of the bottle that melted was…Continue
Some good news:
First the cylinder bodies were all fine. They measured in spec and had no scaring and no signs of warping.
The better news is the cylinder and heads all passed their hardness tests. The minimum hardness of the heads is 85HB and the Cylinders 90HB.
The heads measured between 102-134 and the cylinders 108-118. The lowest values were for #1 head and #2 cylinder.
As expected the bolts were all loose from the…Continue
I need some Rotax advise as my plane is stranded at another airport.
The coolant overflow bottle failed in flight. The first sign was some red fluid in the cockpit a few minutes after take off. At first I thought it was brake fluid.
I noted the EGTs were high, but the CHTs were in range, and the oil temps were slightly high, but not in "the red zone"
A minute later I started smelling something in the cockpit and turned back to the field at reduced…Continue