More success part 2.

I loaded up the mowers and went to Oneco to mow the circle and get in some flights with the Padre. I saw the late sleeper as I was entering the field so I didn't wake him up. The engine ran fine for 3 flights. I had cut out an area between the motor mounts so a metal tank could fit in there. The first flight went well but the tank didn't hold enough fuel to finish the last maneuver. The worn liner in the engine or the wrong size venturi makes it use too much fuel. The other engines use 3 to 3 1/4 ounces for the pattern and this one uses over 3 1/2. The tank holds 3 1/2. I could make a larger tank but I have 2 new piston/liner sets so I'll install a new set instead.
Today is V.J. day parade and it's raining pretty hard at 0630. If it don't stop soon the pig roast at J. Caron's wont happen.

More success.

I went out the other day with the Padre and had the bad engine run again. I changed engines and this one acted up too. It ran fine on the Twister. Now I'm thinking some kind of vibration is getting to the engine. The prop is balanced but the engine isn't really balanced that well because of the design. It needs help. I took a prop washer and cut two sides off of it so it looks like a pie slice. I put it under the prop washer on the engine directly in line with the crank weight. I went out today and the engine ran perfectly. I will continue to use it every time I go out to make sure the problem is cured.

Sucess finally.

I flew the problem .40 this morning and it went fine with the tank relocated on the other side of the fuselage. Must be a fuel draw problem somehow.

Still trying.

I thought I had tried everything with the OS .40 engine. Today it ran very slightly better on 15% nitro fuel. I tried every prop available, every tank, lowered compression ratios but the engine still runs too fast after takeoff. I was looking at it in the shop and remembered a plane I saw at the contest last October. It had the fuel tank on the left side of the plane. Not behind the engine. If I have a fuel draw problem this may take care of it. I drilled some holes and mounted the tank on the other side. Maybe tomorrow I can test it. I got some new piston and sleeves for the .40's today and will measure them to see if there is a difference. Maybe I got a high performance set somehow.

Pictures of my new circle.

The problem post is barely visible but the gravel pile shows up better just to the right of the fence across the runway.

Nearmiss.

I've been flying at the field every day this week since I mowed a path through the high grass and modified the fence a bit. I found a fuel shut off in the fuel line, they can't fool the old guy. Today I wanted to look at the head on the mower as it makes a noise when it starts up and I figured it may be filled with carbon. Overhead valve engine. I set up and got in a flight. At lap 2 I noticed something didn't look right. As lap 3 passed over the fence it struck me that I didn't remove the 2 sections needed for clearance. I backed off and finished the flight.
One of my LA .40's has been giving me trouble. I set the rpm and the engine will speed up and run away. Nothing worked to cure it. I drilled an extra hole in the spray bar, added lots of nitro, changed heads, changed props, same results. I had thought this engine was the one with the worn cylinder liner. I have to use the starter to get that one going after a flight the compression is so low. That is the only thing I haven't tried, lowering the compression a lot. I took the ball end mills and put the biggest one in the wood lathe, set it at lowest speed and pressed the head against the turning cutter. I took some off the combustion chamber but not a real lot. I went outside and ran it with very good results. I will mow the field tomorrow and will try the engine in flight after. After that I plan to go to Oneco and mow that circle. A couple more flights there will let the night worker know I'm still around.

Back to the beginning.

I headed for the r/c field early today. I remeasured the place for the new circle making sure I had clearance from the pipe in the ground. It's 80 feet from the center of the circle. Then I got my push mower running and mowed a 72 foot arc through the hay, which has grown to 6 inches high. I had the mower at it's highest mowing point plus more with the levers resting on the top peg instead of in the hole in the middle of the lever. It took a half hour to get the first pass done. I lowered the mower to the mid range of the adjustment and mowed the outer 12 feet lower to provide a usable runway. I removed the 2 sections of fence and dug out the in the ground support pipes and lowered them to ground level then mowed the grass under the fence. So far so good. I got out a plane and set up next to the pipe as the wind was favoring that spot. I got in four flights and landed in the new grass twice without incident. The winds were very favorable but the temp. was getting high so I replaced the fence sections, packed up and went home.
After about 20 years I'm back to mowing the flying field, this time with other motives. And using the club's mower.