Sticky and Stuck

The mechanic here at Mount Hawley started looking at the plane first thing this morning. We discovered (well, he discovered while I watched :-) ) that this time there were two stuck exhaust valves: number 4 and number 5. Clearly this was not a plane to take into the air. I'm grateful that the engine was making a slightly different sound after the runup because that ever-so-slight hesitation was what keyed both of us to the fact that something was amiss.

He was able to free number 4 easily and it's fine now. Number 5 -- the valve that had the problem before -- is unable to be freed sufficiently well for operation, so Mike (the mechanic) will pull the cylinder and see if he can ream it enough to solve the problem. So the valve is still sticky and I'm stuck here in Peoria for another night.

These problems are inconvenient, of course, but I'm on the ground looking at the mechanic working on my plane. As the old saying goes, it's much better to be down here wishing I was up there than up there wishing I was down here. :-)

We'll get this resolved and 70L will run fine again. Actually, Mike thinks that he already knows what part of the problem is. Airplane engines like mine are air cooled. Under the cowling, there are baffles that direct the incoming air around and down through the fins that cool the cylinders. On 70L, some of the baffles are misaligned or just plain old and tired. That could be allowing the cylinders to heat up, which would cause the valves to stick. There are other potential causes, too, so he'll check primer (for leaks), mags (for timing), and also the carburetor.

The people here have a very high opinion of Mike. He'll find the problem and fix it. Until then, 70L and I are staying put.