912 UL (80hp) - First start of the day

by Nick Anon in 912 / 914 Technical Questions 10 years ago

I want to find out what is considered a "cold start". I have read two different things. One said it's actually based on ambient temperature (cold) and another thing I read said "cold" is considered the first start of the day (not a warm engine). Which is true?

Also, as far as the first start of the day goes and using the choke... Are there any other techniques when it comes to starting the engine, besides using the choke? I have tried this and it works like a charm... Is there anything wrong with this procedure?

1) Ignition OFF
2) Master ON
3) Full Throttle
4) Crank for 2-3 seconds
5) Ignition ON
6) Reduce throttle to IDLE, and she fires right up.

Thanks in advance!

Re: 912 UL (80hp) - First start of the day

by Roger Lee » 10 years ago

Roger Lee

127 5.2k 4.78k

People use cold start in both references. Maybe the most common is first start of the day. There are several terms that get cross referenced.
You shouldn't have to go through that start procedure. master on, choke on, throttle closed unless you have a low idle rpm. (If it is too high an idle rpm and you crack the throttle it will get too much fuel and may not start) If you are one that has to crack the throttle that is all you should do, crack it. If you are supposed to use an electric fuel pump like in a low wing then turn it on. Otherwise turn the key and hold it until it starts. Don't get in a habit of just turning it for a second and letting go and have the engine die. The starter disengages automatically when the engine rpm over takes the starter rpm.

I have started most high and low wing aircraft without an electric fuel pump so I personally don't think it as necessary as some think. The engine mechanical pump does a good job. Every aircraft MFG has it's own likes and dislikes so follow what your MFG says.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Thank you said by: Nick Anon, YEN NIEN YU

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Re: 912 UL (80hp) - First start of the day

by Nick Anon » 10 years ago

Nick Anon

1 2 0

It's a high wing. When we purchased the aircraft, the previous owner said to make certain (on cold starts) that we turn the prop over at least 3-4 times with the ignition OFF before the first start of the day. I think to prevent possible kickback?

So is there anything wrong with the procedure I mentioned above? Am I going to hurt the engine at all? It seems to work.

Thanks,
Nick

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Re: 912 UL (80hp) - First start of the day

by Roger Lee » 10 years ago

Roger Lee

127 5.2k 4.78k

Hi Nick,

There should be no reason to crank this twice. I haven't seen you mention a choke or primer circuit? Just extra wear and tear on the starter. Just set everything and turn the key and hold it until the engine starts. That doesn't mean to hold it on for a minute straight. It should kick and start in 1-3 seconds (normal) and if not get someone to help get the entire system setup so it will do this. If you don't have a choke I would seriously think about putting one in. They are not expensive and fairly easy to install.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Thank you said by: YEN NIEN YU

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Re: 912 UL (80hp) - First start of the day

by Nick Anon » 10 years ago

Nick Anon

1 2 0

Yes, there is a choke. That is what my post is about - trying to start the engine without using the choke. Instead of choking it, can I just put 3/4 or full throttle and crank it that way? Without using the choke. When she fires up, just reduce the throttle setting to idle. She likes to sit around 1700 RPM at idle.

Thanks,
Nick

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Re: 912 UL (80hp) - First start of the day

by Roger Lee » 10 years ago

Roger Lee

127 5.2k 4.78k

Plug gap will play a part. .023 - .027

You should use the choke and try leaving the throttle closed a time or two and then crack the throttle it a time or two and see which works best. Use full choke each time, but only on first start. You may not need the choke on second and later starts of the day.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

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912 UL (80hp) - First start of the day

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