Continental A65 Starting

[wrecker]

Can any one make any suggestions as to how we can improve the hot starting ability of an A65. It will start first swing when cold but absolutley refuse to start from hot.
It has straight mags and I wonder if an impulse one would help. Any Ideas?

[cirrus01]

Yes a impulse mag would certainly help and is probably the ultimate fix. Try in the meantime turning off the fuel supply shortly before shutting down, 15-25 seconds at 1000- 600 rpm. This will drain the carb float chamber. Then when you are about to start the hot engine, turn on fuel for 10 seconds and turn off again. Start eng both mags, throttle closed then when engine runs don't forget to turn fuel back on otherwise within a minute you will have to re-start ! This proceedure seems to work on our C-85 when hot, although it is hardest to start when in between hot and cold..... good luck.

[QNH 1013]

I've not got any experience of an A65 with straight mags as ours had an impulse mag when I joined the group three years ago. Starting was always easy hot or cold unless you accidently primed the engine when it was hot. The cure for this, and it might be worth you trying, was to slowly open the throttle fully (slowly to avoid the acceleration pump priming the engine) and then to wind the prop backwards through a number of blades. This sucks air in through the exhaust pipes to weaken the cylinder mixture.
At the last mags change (about two years ago) we changed from Bendix mags with a single impulse mag to Slix mags and both of these have impulse couplings. Starting is just as good as before. Hot or cold the engine normally starts on the first blade after the mags are switched on. When the engine is hot, eg after refueling, we don't even pull through a couple of blades - just mags on, and it will start on the first blade. The only time we have any difficulty is when its neither hot nor cold, say 30 mins after a flight, and its not clear whether to prime or not. We always try without priming first because its easier to add fuel to a weak mixture than remove it if you've overprimed.
Wonder if you ever get a kickback without an impulse mag? In 3 years and 250 hours I've never seen a kickback with our A65.
We bought the Slix mags because they did an offer and took the old bendix ones in part-exchange. Memory says we paid about £800 for the pair.
We had the engine zero-timed this summer (after 2600hours) and that cost ten times as much !

[wrecker]

many thanks for the useful suggestions.I will have a try when the weather again gets flyable. With regard to Kicking back we do have a problem but very infequently

[poetpilot]

Without wanting to complicate things (but doing it anyway) we get a bit of a kickback problem cold with our A65! Each engine has its own idiosyncracies it seems...

I'd endorse the "wind it backwards" routine to weaken the mixture in the pots (just remember to RESET THE THROTTLE before attempting restart), and the addition of an impulse mag as a positive advantage.

Is your prop correctly positioned on the crank for a decent pull through? 10 to 4 (if it was a clock) is about right, ours is currently about 5 to 5 and this doesnt give us the best pull through. In fact, I've found it easier to pull from the bottom, which also enables me to walk away from the prop as I do it...

[ 12 October 2001: Message edited by: poetpilot ]

[ 12 October 2001: Message edited by: poetpilot ]

[LowNSlow]

I had a Cub with an A-65-8 with no impulse mags. A kick back was not uncommon when the engine was just warm. Cold no problem with 3-4 shots of primer, hot no problem after 4 blades with the throttle in the start position. Warm, nightmare. I was eventually told that one mag should probably be retarded slightly. This is the one with the greater rev drop when the mag check is done. Starting on this mag only should reduce the possibility of prop kickback and truncated fingers. It worked for me :D