ORIGINAL: ludal
Hi,
I have a saito 100 which can't manage to suck fuel right. I thought I had an air leak in my tank system but I changed all the tubes and the tank and the problem persists. When I push the thottle air bubbles appear in the tube that brings fuel to the carb. Sometimes the engine seems to work fine on the ground but it it stalls during the flight.
I recently adsuted the valves, so they're ok.
Can someone help me? I'm really sick of this engine, and I hope some saito expert on this great forum will convince me that this brand is not crap!
Cheers,
Ludo, France
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I have eight, or more, Saito engines and I am quite frugal. These engines would not be in my ownership if they were not good engines.
What you are describing fits the "fuel foaming syndrome". If the fuel tank is rigidly mounted to the model, the engine's vibration shakes the fuel tank so hard that foam is formed and picked up by the pickup tube. The solution is to isolate the fuel tank from the model (or test stand, if that is the case) so that the fuel does not have an opportunity to foam in the first place. Some models being sold are designed in such a way that it is very difficult to accomplish the necessary isolation.
Packing the fuel tank in loose foam is the answer, if there is space to do so. If not, a few squirts of Armor All plastic finish restorer in a gallon of fuel will usually alleviate the problem enough to tune the engine and fly successfully. While the Armor All works the majority of the time, it is masking the problem. It is better to fix the cause of the problem in the first place.
As your Saito engine accumulates running time, it will smooth out and not shake/vibrate as much. Be patient and stick with it. You will overcome this problem, one way or another.
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Addendum:
JettPilot is on the right track suggesting the felt wrapped fuel pick up inside of the fuel tank. I haven't tried the felt in a glow engine, but I know it works from watching others using this "trick".
I use a Dubro sintered bronze fuel pick up, which works on the same principle as the felt.