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Old 10-16-2007, 06:54 AM
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MJD
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Default Magnum tank installation

Nothing earth-shattering here, but someone had written me privately asking about tank options for the Magnum and I shot a couple of pictures of mine. So I thought I'd post them in case they are of interest to any other Magnum owners.

The tank used is a Jett 8 oz. "standard", which is 2" OD by 5-1/2" long. It's fits perfectly in the tank area, and juts out a bit into the radio compertment as you can see - which doesn't matter one bit since everything is aft of there anyhow. So far (knock on wood) I have not had one bad run, or blown a single plg, in fact after 30 some flights I am on the same plug and it still idles and transitions just fine. Also shown is something I did to satisfy myself that there wasn't a long length of silicone tubing flapping in the high speed breeze, which is a length of 1/8" Al tubing coupled to the pipe pressure tap and running between the pipe and the fuselage to the tank pressure inlet. Normally it is pinned down - originally it had a clip bonded into the fuselage side where that small chunk of silicone tubing is positioned near the middle, but I did a lousy job on the clip and it eventually came out. So the simple and obvious fix was simply to tie-wrap it to the pipe coupler. You don't see that here because I just trimmed the header a bit more and reinstalled it and haven't put a new strap on yet.

Anyhow, for those that haven't used them before, bladder tanks are dead simple to use, and since my experience with them in the Magnum I have installed them in a couple of other sport aircraft as well.

Bladder tank or no, I now make it standard practice to kill the engine in flight rather than let it run dry, and I am sure some are thinking "well, of course you do that silly!". Although I let it run dry a few times with no apparent problems (note that I do avoid the temptation to keep cranking the needle in for those last 37 rpm..) the problem is that I finally realized that every time I had a problem with the prop stopping near TDC, and thus hanging down to snap off on landing, was when I let the engine run dry. When I kill it in flight from full throttle, so far (knocking on wood once again) it has come up against compression and stopped horizontal every time.

Cheers

MJD

p.s. I took the foam off the Rx to see the back of the tank - yes it is usually wrapped!
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