National Aeronca Association Bulletin Board

When we flew 1706E last week, for the first time since I bought it(OK I admit it I let it sit for several months... alright 11 months, stuff happens) we found that the airspeed indicator was irratic(pitot and static are clear) and that the engine seemed to overdrive the prop by 100-150 rpm above red line in full throttle level flight, you know like when you level off and let it pick up speed before throttling back. It performs fine and I have a new Sensennich 72/42 ready to install. My questions are 1. Does anyone have a favorite shop from which to obtain an ASI? We've dealt with Century for years and the young lady there says that they don't have any of those low reading ASI's and that they are scarce. 2. Is there such a thing as a tach that reads high? I understand friction causing a low reading but ???
We're gonna check the tach with one of those electronic tach thingamajigs before we install the new prop but would like to know if anyone has experienced this and why.

Tom Seevers
Delaware Ohio

Tom,
Any good shop can do the indicators, I've used Otto's out here in CA. As for the prop, check the numbers, you shouldn't be able to overspeed the 72/42. I have run as low a pitch as 38" with out any problems. Make sure it doesn't overspeed static, and count on 100-200 rpm increase in flight. The higher the T/O rpm the more power the engine will make, in flight close the throttle to keep the RPM down. But, you need enough prop to pull the plane around. I'm assuming this is an A65.
Paul

I guess I wasn't very clear. I have a 72/42 to put on the A65 but am using a Flottorp 72/48. That is what is causing the possible overspeed. Full throttle in climb is about 2250 and in level flight is 100-150 higher. To indicate 2150 I'm using 1/2 throttle and of course because of the irratic ASI I can't give you indicated airspeed. Seems slow, which would lead me to believe that this Flottorp prop is just not right regardless of the pitch number.

I'm hoping to find a 0-140 ASI that I can use to replace the problem (I 'm not gonna use the term inoperative although it might as well be) instrument but they are apparently rare now days.

Good news? The airplane is straight and rigged well. The performance is as expected with an A65 and I'm enjoying flying it by "feel".

Tom, a possible source for an old ASI would be E-bay, they do come up on occasion, but not too often. Obviously you would probably have to send it in to be overhauled after you bought it though.
I found a 0-140 on E-bay a few years ago to replace the 0-160 I had on my Champ for many years. I sent it in to Keystone Instruments in PA to be overhauled. You could call them and see if they might have any in stock, it's worth a shot.

http://www.keystoneinstruments.com/index.html

I had a bad experience with Century several years ago. I bought a Bonanza that had been re-furbished, including a re-built ASI. On my trip home, the just overhauled ASI stuck on zero. I called Century, got hold of a very helpful gentleman who looked up the work order and stated "I want that instrument back, that shouldn't have happened". I overnighted it and waited a couple of weeks (while my new airplane sat in the hangar). I finally called, a surley woman stated that the instrument had a "bad jewel" and needed to be overhauled. I explained to her my p[revious call, and she said that guy had no authority to tell me that !
If I wanted the ASI back, it would be 200 and sumthin dollars. Being anxious to fly, I paid the bitch and got my ASI back. To add insult to injury, I had to wait 2 more weeks, and when I called to see if it was done, I learned it had been sitting, ready, for several days. I asked that they overnight it and charge me. They did, three days later!

A couple of years later, I ran into a rep of theirs at a trade show and started explaing (very politley and calmly) my experience. He listened for a minute or so, then turned and started talking to someone else about something else. I waited a few minutes, then walked away.

After telling my story to many folks in the aviation community, I heard about other such experiences.

I checked with Keystone and was told that they don't have one and they don't have any rebuilt ASI's on the shelf. " Can't keep up with the work we have let alone get ahead."

Sorry to hear about your dissatisfaction 'Dreamer. They have always been great to us.

Been through about all of the overhaul shops and a couple of new distributors and can't find a 0-140 ASI. I'm about to give up and install a 0-160.

Still would like to know if a tach can read erroneously high. Low seems possible due to friction but high?