QuickTalk 11 - QUICKIE HINTS
- Category: Q-Talk Articles
- Published: Wednesday, 31 August 1983 07:11
- Written by Jim Masal
- Hits: 1149
From Bill Dvorak, #451:
1. Don't even bother spraying Feather Fill, as too much is wasted. Brushing works better and is much more economical.
2. (Page 8-3) I am 5'11" and could not reach my rudder pedals as mounted per plans. I mounted them on the canard and found they work with less effort and are easier to reach.
3. ((Page 17-5) Check the clearance of your exhaust pipes before drilling the holes that mate the two halves of the cowling together. If you don't, the hole nearest the firewall will probably be cut away when you fit your pipes.
4. If you worry about the first time you have to put fuel in your tank, then try what I did. I put a balloon over the fuel outlet from the tank, sealed up the cap and drain, then put a little air in the tank. Use an old tire stem in a cap that will fit your filler and make sure everything seals well with a soap and water solution. Pump enough air with a bicycle pump to inflate the balloon. Then put a mark on the balloon and measure it. Check the mark later to see if you have any leaks. Be careful to only use enough air in the tank to fill the balloon as too much pressure could damage your structure. Also, if you use silicone to seal the cap, be careful not to let any get into the tank. It really swells when it meets fuel.
From William Adams, #528:
1. (Page 17-14) Another builder and I had a problem, which resulted in a 400-500 RPM loss. Evidently in the initial mounting of our Onan engine, the throttle cable was connected to the governor arm so that when the throttle in the cockpit was shoved full forward the butterfly in the carburetor was wide open. BUT, there was NO extra space left between the throttle handle in the cockpit and its forward stop when pushed wide open. I have to assume that when the engine has been mounted for some time there must be some "settling" which causes forward and downward movement of the engine (It doesn't take much - 1/4" will cause the problem). This movement in effect causes the throttle cable (which is fixed in position) to pull the butterfly linkage resulting in a slight closing of the valve. This can be checked easily by having one person push the throttle wide open slowly in the cockpit and at the same time a second person should then attempt to further open the butterfly at the carburetor with his finger on the valve extension. Unfortunately, this problem is not easily detected by checking engine RPM in static run-up due to vibration, RPM instrument error and fluctuation, etc. It becomes painfully evident in flight, however when you still develop the same RPM in climb and level flight that you did in static test on the ground. A builder can prevent any possibility of the problem arising by installing the throttle so that when it is pushed wide open there would still be approximately 1/4" to 1/2" of throttle shaft still visible in the cockpit. This would allow for "settling" with the engine later.
/Ed. Note: After discussions with builders having similar difficulty, it appears that the rubber engine mounts take a compression 'set' over time due to the weight of the engine. This would explain the downward and forward movement described by Mr. Adams./
From Mike Conlin, #60:
1. (Page 17-4) It's really not smart to try and find the proper spacer length (ESM1-1) while fighting the chunk of lead we call an engine. Either use the actual engine mount (off the engine) or make 1/4" spacers in order to pre-load the rubber bushings. Also, if you start with the spacer length they call out and add small spacers in 1/16" increments, you can get it perfect. Once the proper length is known, then make one the right length for permanent use.
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