Cold (cool anyway) Weather Operations

[James Turner]

Hi All,

I'm after some advice on operating my 24-180 in cooler weather (around 2-3 degrees C). My aircraft is kept in an unheated but otherwise dry and modern hanger. The last couple of times I have flown, the engine proved difficult to start with the battery proving too weak. When I arranged for an external battery jump start the engine still required longer than normal cranking times to get running.

After an hour's flight the engine starts perfectly. I should also say that it has started without fail on every occasion in the warmer weather. I am going to replace the battery today.

For priming I have been told not to use the primer but instead to pump the throttle 4-5 times for a cold start and once for a warm start. I've owned the aircraft for 8 months now; this is my first winter with it.

Any advice?

Cheers,

James.

[Michael Bryant]

James,

I am fairly new to Comanches, but if I am correct, pumping the throttle activates an "accelerator pump" in the inverted Marvel-Schebler carburetor. Especially if there is no airflow, raw fuel will actually fall in a downward direction into your intake. If you have a backfire, it can light the raw fuel in the intake and cause a fire. I would use the primer for priming.

Hope the new battery solves your starting issues.

Michael

[JIMICS2452]

Use the primer, especially in cold weather. That's why it was installed.

[N3322G]

James,

Welcome to Comanche ownership.

Using the primer is good advice and I would add to fly every week or more frequently will keep most everything in better working order

[Duane Bolin]

Had a similar problem with my 180. I have been through 3 batteries since 2007. My first problem was the 11 foot cable from the battery to the start solenoid was still aluminum. That was the first change, but still had problems. I then cleaned all the grounds (strap from engine to motor mount and the ground at the battery box to airframe) with a dremel tool and wire brush. I finally wired in a battery minder to the battery and it is plugged in all the time the aircraft is in the hangar. The last battery is slightly over two years and going strong.

I use the primer all the time. I use a few more strokes when it is cold and only about 3 when it is warm.

Might also check how long has it been for a mag overhaul, and what condition are the plugs.

[Andreas Riedel]

Hi James, congratulations to your 180. I am based in the mountains with many cold starts in the winter. I have changed to a Concorde battery which give me more power and they last longer. Had to change the Gill every two years.
andreas

[Jay]

On top of using the primer, Using the appropriate grade of oil (or a multiviscosity oil) in cool weather helps some, IMHO. I'd also recommend a battery tender that is appropriate for the type of battery in your airplane. These are not trickle chargers, you can leave them plugged in and they will desulfinate your battery and extend it's life. I use a BatteryMINDer myself, available from several sources online.

If you still have the aluminum battery cables you should consider swapping them for the Bogert Aviation STC'd copper cables. That makes a huge difference, especially if your airplane has a lightweight high torque starter.

All the best,

Jay

[James Turner]

Thanks everyone for your comments.

I replaced the battery yesterday and will use the primer from now on. I'm not sure about the battery cables but will check them out also.

This forum is a wealth of information. Thanks again for your assistance.

Cheers,

James.

[Matt Bogard]

I'll echo what has been said above as I had the same experience last winter. I installed a new battery (Gill G-35S) and bought a BatteryMINDer at the same time. I have the pigtails wired to the battery and can easily plug it in in the luggage area when the plane is in the hangar.

I just had the Bogert copper cables installed as part of my $8,000(!!!) annual a couple weeks ago and I'm really surprised at how much faster the starter motor moves the prop now.

I installed a Reiff preheater last winter that wraps around each cylinder and has a good aluminum block heater on the oil sump, and I'm running XC 20/50 year-round in Nebraska. I plug the heater in 12-24 hours ahead of a flight if it's below 30 degrees F out. I've found that 4-5 primes in the winter and none in the summer works really well for my O-540.