ORIGINAL: Electric Delta
The stock Magnum tank is around 7.5 oz. I replaced mine with a 6 oz. Bubble-Jett tank, because that's what I had on hand
for my Q500's, and got #1) steadier running and #2) longer run-time than with the stock tank, in spite of it being smaller.
The stock tank fits so tight, there isn't much room for any padding, you WILL get foaming. The Bubble-Jett 8 oz. standard
tank also ought to just fit, and would be my first choice. Just my $0.02. Good Luck!
I use an 8oz Jett tank on mine, and get a good run right to the end, altough wise folk shut down before you get there. Engine never hiccups or acts up.
9-6 APC, 10% synthetic fuel I tached about 18k running in a fat 2-cycle. This is a good prop choice for the trim flights. Weston recommendations are stock header for 8-10 (lousy prop but anyhow..), 1/2" off for 8-9, 1" off for 8-8. It is a good idea to pick up a few APC pylon props in the 8-9.25 pitch range, and experiment with those rather than dicking with sport props at near 20k rpm.
Hand launches are a cinch with the 9-6, not much problem with the 8-8, throw harder with the 8-9, and I have not used the 8-10 yet but hear lanuches are dicey. Don't have a wuss toss the airplane, get someone on it that will give you some airspeed, and lay off the sticks until it has accelerated, well unless you have to do something that is!
I rebuilt the elevator linkage after hearing more than one horror story about elevator failures with stock hardware. I too use heavier servos, no reason not to, right?
It is NOT a 200 mph airplane. I would be surprised if mine has bettered 150 mph.
When you are tired of the Magnum, you could always bolt the West .50 to a Q500 ARF.
Magnums glide like an F-4 Phantom. When the engine quits, glide fast, turn easy, set up and land now. Put some skid tape on the belly.
It's a fun airplane. Oh yes, don't overdo the control throws either - expo is always good, I don't use dual rates anymore. First time I flew mine I snapped it in the first turn after the engine quit. After cinching up the cuffs on my pantlegs, I landed okay, but decided I would not do that again, and removed the offending elevator throw.
Fly with the rearmost recommended CG - the recommendations are very forward, which makes it "groovy" but a ***** to flare at all and really heavy in the turns. If you lay out the planform and do a standard NP and CL workup, you'll be surprised where it tells you the CG should be - 190mm or more from the LE. Some Euro fliers fly them there apparently, but I would wait until "later" for those experiments.
MJD