'OS MAX FP 40' Unable to start.....

Change glow plugs.

Use fresh fuel.

Make sure you've got a good battery to drive the glow plugs.

Don't flood the engines.

Main needle valve out 2.5 to 3 turns.

Set low-end needle so that 1/2 of the air bleed hole is open.

Listen to what the engine does and react accordingly. If it sounds rich, lean it out; if it sounds lean, richen it.

It's easy to bend the connecting rods on the FPs if you flood the engine, so be careful. If the engine gets flooded, take the glow plug off, get all the fuel out, and try again.

You might want to look around for someone who can help you play with the engines, just to get them going.

Marty

Hey Martin, my OS 46 starts with main needle out 1 1/2 turns. I am a newb though. Just wondering if that would be a better starting point.

And, we had a fella out at the field who was given an old Avistar with a fp .40. The motor pulls that plane really well. It seems to have alot more power than the new .40 la.

The venerable 40FP is a pretty user-friendly engine. Fresh fuel, a good glow plug (mine liked the Fox long idle bar plugs, although the OS A3 would also be a good choice). Some FPs need to have the idle screw removed to keep them from loading up.

Morris

I always start a new or unknown engine with the main needle 2.5 to 3 turns out the first time to be sure it's not too lean. I then turn the needle in until I get the best performance. It's very likely that 1.5 turns works best for you.

I always use the 'pinch' test to fine tune. With the engine at full throttle, pinch the fuel line momentarily. If the engine speeds up, it's rich, if it slows down, it's lean. You should be able to pinch the fuel line momentarily (.5 second or so) and there is no change. If anything, I stop when it speeds up only slightly, meaning the engine is slightly rich. I run my engines slightly rich and have never burned one up. they last a very long time if you don't lean em out too much and cook 'em!

I can start any glow engine with the carburetor removed from the engine. Practice starting the engine with the fuel line removed. Then you too can start any glow engine in just a few flips.

The needles have no affect until the engine is already running, unless your fuel tank is improperly installed and fuel is siphoning out of the tank and flooding the engine. If this is so with your engine, fix the fuel tank problem before worrying about the carb needles.

These engines are unlike any other type of engine that you will handle in your life. They do not generally have fuel pumps, regulators, etc. There are some exceptions, but your OS .40FPs are not one of them. You have good engines, by the way.

While glow engines are different than other engines, they are easily mastered.

As others have mentioned, you need a good 1.5 volt source of DC electricity. If it is weak, it will make starting difficult. The engine needs a few drops of prime (fuel) in its combustion chamber. Open the carb all the way up, put your thumb over the carb opening to seal it from outside air and then flip the prop two or three times. The latter works best when the big needle valve is open 1.5 to 2.0 turns. OR, if you have some fuel in a small container, squirt three or four drops of fuel down into the carburetor. With one of the latter accomplished, smartly flip the propeller four or five times. Now connect the glow plug battery. Hold the model firmly, pull the throttle all the way closed via the transmitter and then open it just a noticable crack. Begin flipping the engine smartly. Smartly means accelerating the prop through top-dead-center (highest compression). Limp wristed flips usually won't work. Your engine should fire up within one, two or three flips.

Before all of this, I should have had you pull the glowplug, apply voltage and look at the color of the glowplug as it lights up (glows). It should be a bright orange. Dull red is no good.

Good luck and let us know how you fare.

Ed Cregger

It could well be.

I tend to start on the rich side and work in.

That's my impression, too.

Marty

Sorry, what I meant was the manual has you start at 1 1/2 turns out for a .46. I was thinking that might be a good starting point for the .40. Mine actually stays close to that. Maybe add a few clicks here, take a away a few there. And the tuning by pinching the fuel tube, that is the way to go. I was having some troubles witha tower motor and finally got smart and read the manual. (originally thought, "what the heck, its just another .46"). The pinch method solved all my problems. I am also one to run a couple clicks below high rpm.

hai guys, i just had a new os 40 engine, past three days i am trying to start my engine as per manual. but im not able to start, please any one advise me what are the starting equipments are required.

after connecting the glow plug with 2.0v dc supply , i used my hand to twist the propeller to start the engine. is it ok ?

or any other starting equipment is there to start the engine?

kindly guide me,

Your first mistake was connecting your glo plug to a 2.0 volt supply, these are usually a 1.2 to 1.5 volt plug. You may have burned it out.

Red S.

I prefer to use a "chicken stick" to flip the prop. Sticks are easier to repair than fingers. :o(

Combustion requires fuel, air, and ignition in the right mix.

Attach the propellor to the engine so that the propellor is close to 9 o'clock and 3 o'clock as the compression cycle starts.

To get fuel to the engine, open the throttle to its maximum with the glow lighter NOT attached. Put your left thumb over the opening of the carburetor (the venturi). Flip the prop smartly five or six times with your right hand. Watch the fuel line to see that the fuel flows to the needle valve nipple.

You can achieve much the same thing by putting a finger over the end of the muffler. Excess "back pressure" from the muffler tap will cause the fuel to run to the carburetor more easily.

Lower the throttle to idle (the opening in the carburetor should be about 1/32"). Attach the glow lighter. Flip the prop. If it is very difficult to flip it through compression in the right direction, you can try flipping it in the wrong direction--when the engine is loaded with fuel, bouncing the prop BACKWARDS often causes enough combustion to then make the engine fire in the right direction.

There are electric starters that can help get a balky engine going, but you have to be very careful with the FPs not to flood the engine and bend or break the crankshaft as a consequence. If you do get the engine too full of fuel, you should take the glow plug off (a good time to check that it glows red-hot--that also helps burn off the excess fuel from the coil) and pour out the excess fuel.

You can also put a cloth over the glow plug opening and spin the engine with an electric starter. The excess fuel will spray out the top.

I much prefer to start FPs by hand, but I've seen people do very well with electric starters.

If and when you get the engine to run a little bit, you then have to adjust the needle valve to the right setting. This is done by ear and by experience. If the engine is rich, it will burble and not run very fast; if it is lean, it will rev higher and higher and then quit.

Setting the idle using the air-bleed screw is a whole 'nother dark art. For starters, the screw should cover 1/2 of the air-bleed opening. You can use the tip of a #11 blade or a pin to help you feel where the end of the screw is.

Hope this helps.

Marty

Pull the plug and attach a 1.5V cell to it and make sure it is not burned out from using 2V. Let us know. If it is still ok or if you put in a new one and it still does not start, using 1.5V, then we can help you with some suggestions. Gord MAAC6694