What are some tips for starting a cessna 152?

Question

When the engine is cold, why does it start better with the carb heat on?

Why does it start better when I pump the throttle a couple of times? - I know too much of this will start an engine fire in warm weather.

Why does it need more prime when it is cold?

While starting, how can you tell if it is flooded? - Can you hear the difference?

Answer 1

The quick way...

Master Switch ON

Check Fuel

Avionics Master Switch ON

Mixture CUT

Throttle OPEN 1/4 inch

Parking Brake OFF - Fuel Selector BOTH - Fuel Shutoff IN

Beacon Light ON

Feet on brakes

Start Ignition, Mixture FULL RICH when engine fires

Make sure everything is in the green

And it is ON...

Answer 2

I think you 152 may have a blunger primer system, with this system, you pump the throttle a few times 2-3 and it eliminates the use for a primer. That's how I've always started a 152. As for the carb heat...I wouldn't recommend using this for starting the engine,because the use of carb heat,means the air source to the carburetor is unfiltered,thus stones and debris on the ground can get into the system. The emergency procedure for engine start in air after engine failure includes carb heat ON,because the engine may have stopped due to carb ice, and this increases your chances of getting it running again. I hope this helps.

Answer 3

I'm not trying to be rude or anything ,but Isn't this something your flight instructor should have covered with you? Or will be if you are a flight student?

From your previously asked questions I assume you're not a flight student. Probably pretty bad idea for anyone here to give advice on starting an aircraft! THINK PEOPLE

Answer 4

a good trick for starting a carbureted engine when it's cold is to prime it as you would normally do, pull the primer out and as you begin cranking the starter, slowly push it in.

If it's very cold you should have it plugged in or use a Red Dragon.

Answer 5

You should never start an engine with carb heat on, it bypasses the air filter.  

If the engine starts better with carb heat on, it is because the air filter is dirty and is blocking the air flow, or there is something wrong with the controls.  This could be serious, get a mechanic to check it out.

An engines starts better with a slightly rich mixture, if a carb has an acceleration pump, that can then be used to enrichen the mixture.

Not all carbs have acceleration pumps.  

When starting, in most cases you are better off priming rather than pumping the throttle since the primer injects the fuel directly on top of the intake valve and the carb acceleration pump does not.

Answer 6

Go over it with your instructor, please.  Follow the checklist, and assume that if it doesn't want to start, there is something wrong, and a mechanic should look at it.

Remember that fuel is as explosive as TNT, and treat it with the proper respect.

Answer 7

Carb heat will remove all the ice layer, if any. Even if ice layer is not present then it will make the mixture quickly combustible. But normally carburettor heat is kept COLD (fully in) during the start up.

Though excessive pumping will lead to overflow, however, if you are pumping 2-6 times (that is recommended) then you are doing it right.

So that a rich mixture helps in starting the engine (Mixture is generally RICH--full in-- below 3000 feet density altitude and lean to maximum RPM at full throttle at higher density altitudes.

You can smell it in the cockpit. Secondly, the engine will throw a lots of exhaust (white in color) as unburnt fuel once the engine starts rev up. Thirdly, the engine will be comparatively a bit slow in the beginning then picking up quickly.

Nevertheless, I would say that a qualified flying instructor would be a best bet for learning & developing good flying skills.

I take pleasure in providing additional information for flying as given below.

Happy flying!

Answer 8

I have never heard of starting a c152 with carb heat on.

Using a checklist is the only way to start.

Being flooded the engine will not start at all, and usually can be corrected by pulling the mixture to cut off.

Primer will pump gas right into the carburator to help the engine fire up, but too much will flood out the engine, becasue it will not mix correctly to form a combustible mixture, and also will be a fire hazard becasue of the pooled up fuel.

I have found that advancing the throttle after shooting about 3 shots of prime help the most, the openig of the throttle will allos the fuel to enter the intake and help start the engine.