Today was the day to test the Cessna, to see if it's ready for the next steps before a maiden. With help from my son, we brought it up from the basement workshop and out to the garage. I added some fuel and turned the prop by hand with my thumb over the carb to really pull fuel in. From the first time I fired the engine I knew it wanted to be really wet first, which happened quickly. I don't have a starter powerful enough for an engine this size, so we hand-propped it. After a half-dozen flips with the choke on it "popped", so we took the choke off and after another dozen flips it fired to life.
I quickly determined my throttle servo setup needed a lot of work, as I couldn't get it down to a low idle and there was too much flex in the line. I've got a fix in mind for it, which won't be too difficult.
The first time I fired the plane up I had a lot of electrical interference that was making the tail surfaces jump. When I fired it up today it looked much better, although after running it for a while I noticed it was still an issue...
Since the first run, I've removed a lot of excess wiring and cleaned up the rest of it that remained, but still the issue. Since the ignition module is forward of the firewall, I've got no metal pushrod (or anything else) connecting to the engine or ignition, etc., I'm now thinking the interference is coming from one of the old existing servos. At least one of them has been spliced, and they are of unknown vintage/quality/condition. To be safe I'm going to buy replacements for all servos, and will start with replacing the ones I doubt the most (throttle and nosegear). The rudder and elevator servos all appear fairly new and are the easiest to replace.
So back to the bench with it!