First Engine Help - Evolution .46
 

Happy Holidays everybody! I am preparing my spad3D for its first flight tomorrrow and spent all day with the engine. I must have run 4 tanks of gas through it. I am comming from alot of experience with gliders, so I am kinda a neophyte. Got a few questions before I fly tomorrow.

Question 1: I am getting what appears to be black seapage out of the back part of the muffler. The muffler has two parts, a forward 2/3 and a back 1/3. The seapage is comming out through the seam. I checked the bolt/screw that holds them together and it is tight. Is this normall?

Question 2: Adjusting the idle. I think I got the high speed needle adjusted right. Once i give full power and it "spins" up, it seems to hit a peak sound and stay there. No wobbling in sound, nice and steady high pitch roar. However, when I go to advance from idle to full power, I got to go real slowly or it goes back to iddle and dies. I've tried adjusting the idler arm as they call it, but no matter where I go I can't seem to fix the problem. I have started form both ends and worked in to a sweet spot, but even then I have to go slow up to about 40% throttle till I can do whatever I want or it goes to idle then dies. The directions are no help, I did what it said and it's not working!! What's wrong? I am not a ME-262 pilot here ok! hehe

Question 3: The line from the muffler to the gas tank I guess puts pressure on the tank acting as a "fuel pump." Well, I am getting a brownish stain on the inside of the tank where that return line is. Is that normall? I also noticed that the wing is covered with brown spots from the exaust. The exaust gas looks whiteish. Is this the fuel or am i running it too lean/rich?

Those are "all" the questions I have. Only, hehe. Well, thanks for the help and Happy Hollidays!!

RE: First Engine Help - Evolution .46
 

Chris,

While the Evo was tested by prominent R/C magazines and was found to be a high performance, well made engine, I believe even new modelers should be tought to run and to adjust engine by being "thrown into the water" and being forced to start swimming... Not with concessions and "E Z Adjust" engines.

In your post, it is not clear if you tried to adjust the idle mixture needle.
Since you are new to engines, you will first have to learn to determine, by its response behavior, if your engine's idle is adjusted too lean, or too rich.


I copied this from a previous post, that I replied with to another asker...
I adjusted the reply for your Evo...

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Start the engine and advance the throttle slowly to full power. With the nose pointing straight up, adjust the main needle 100-200 RPM richer than maximum (lean it to max and then open it a few clicks).

Lower the plane to level attitude and close the throttle to idle; about 1mm from fully closed. Now listen; if the engine is gradually slowing down, it is too rich. If, on the other hand, it is speeding up gradually, it is set too lean.

Because adjusting the idle needle requires close proximity to the spinning prop, some will say you should shut the engine down for adjusting this needle. If you are sure that you are competent enough, you can do it with the engine running at 1/4-1/3 throttle. Adjust this needle at flying attitude (level for most planes)

Let us assume you determined the idle is too rich. Close the idle needle very little, run the engine at full throttle for a few seconds, to clear it of excess fuel and close the throttle back to idle. Listen again as described in the third paragraph and repeat the adjustment in ever smaller incremental changes, until the idle speed is steady.

If the idle was too lean, do the same, but open the idle needle a little at a time, instead of closing it.


Now the transition test. Your idle is steady. Run the engine at full throttle for a few seconds and close the throttle to idling position. Allow it to idle for 30 seconds (which may seem longer than you think...) and open the throttle to full QUICKLY.

If the engine ran to full immediately and rapidly, you are done. If it hesitated; sort of choked and then sped up to full (or died), it is a bit too lean. Open the idle needle very little and repeat this test.

If, on the other hand, the engine sputters (and sometimes spits fuel out of the carburettor), before speeding up, or dieing, the idle circuit is set a little too rich. Close the idle needle very little and repeat this test.


Do this until you are happy with the idle quality and the response. If you are flying a 3-D model, you will need the idle set richer than a regular plane, because the engine must overcome gravity, to get the right amount of fuel for a good transition and part throttle operation (the idle needle controls the fuel mixture from 0-80% throttle).

RE: First Engine Help - Evolution .46
 

Dar covered everything quite well as usual...Except, the reason you get the black residue out of the muffler, even though the bolt is tight, is because there's a baffle disc inside that "frets" and there isn't much you can do about that. Except maybe remove it, but then you wouldn't have enough tank pressure. If you can figure out a way to keep that alum. disc from chafing/ fretting let me know! I tried JB weld, silicone, but they disintegrated...