The Cessna 120-140 Association Forum

What advice does anyone have for a hot start procedure?

I I have a MS carburetor on my 0-200 and I always shut it down bu pulling the mixture to full lean or else shutting off the fuel and letting the engine run until the fuel in the lines is exhausted. If I start the engine while it is still hot, just one pump on the throttle and it always starts on the second or third blade.

8224 wrote: ↑Sun Jul 05, 2020 11:55 am I I have a MS carburetor on my 0-200 and I always shut it down bu pulling the mixture to full lean or else shutting off the fuel and letting the engine run until the fuel in the lines is exhausted. If I start the engine while it is still hot, just one pump on the throttle and it always starts on the second or third blade.

Same here with a MS carb and a C-90.

Thanks, gentlemen. I'll try that.

We also have MS carb and always fires right up after gas stop. I'd say best you can do is NO throttle to start with?

8119 wrote: ↑Sun Jul 05, 2020 1:46 pm Thanks, gentlemen. I'll try that.

Not to play the devil's advocate here, but....

Have you ever seen a picture of an 0-200 that caught fire after someone pumped the throttle before starting the engine? Marvel Schebler carburetors installed on TCM 0-200 engines are equipped with an accelerator pump that squirts a small stream of fuel up into the throat of the carburetor to help prevent hesitation of power when applying throttle while the engine is running. If the engine isn't running pumping the throttle will cause that stream of fuel to fall back down through the carburetor into the airbox attached to the bottom of the carb. A backfire through the induction system during start could cause that fuel to ignite if the engine doesn't start.

If the engine installed in your airplane is difficult to start when hot, take a look at other areas that may be a problem such as the carburetor or ignition system. Nowhere in the aircraft or engine manufacture's instructions for operation for aircraft equipped with an 0-200 does it recommend to pump the throttle to aid in starting.

Mike makes a very good point. Way back in the dark ages, I was taught not to prime or pump the throttle unless the engine was turning over. It's not so bad with larger engines where the priming is at the intake ports, but on A- and C-series Continentals, most of the fuel is going to drop down into the airbox.

If you do get a backfire, keep cranking! The hope is to draw the fire up into the engine where it doesn't cause problems.

Oh, my hot start procedure (Stromberg carb) is to crack the throttle about 1/4" and crank. It usually starts pretty quickly.

As previously said crack the throttle and ours fires right up when hot. It was that way with a C85 and now the O200.

OK, no pumping the throttle.
My engine starts immediately when cold with a couple of shots of prime. I get fuel at a different airport and am ready to start after 15 minutes sitting on 90-degree-plus days. That's when I have a problem starting. Throttle cracked 1/4 and crank forever.

Define "1/4" -- inch or throttle travel?