Anish,

With the piston at top dead center (TDC), screw the contra down until it touches the piston. Now back off one full turn. This should get you in the ballpark for compression setting.

DO NOT hook up the tank.

If possible, get some commercial fuel. If not possible, up the ether content to about 40%. A commercial fuel will eliminate one possible starting problem.

Use an intake prime by adding a couple of drops to the rear intake. Do not squirt a bunch in, just two drops.

Now flick to start a few times. If the engine pops before hitting TDC (kicks back) lower the compression 1/8 turn and try again. BTW, you might want to use a glove to protect your fingers until you find the correct setting.

If the engine does not fire, increase compression and try flicking again.

When the engine fires correctly, prime it and try again. When the engine fires easily with a prime, hook up the tank with the top of the tank below the venturi level. Open the needle until the fuel just starts to flow. Now start it with a prime as before.

I did not see prop mentioned. Use a larger than normal prop (~ 9x4) at first to get the flywheel action. After you have it running well, you can switch to a smaller prop.

Don't give up.

George