Hot engine starting

Guest Discussion
21

…and just like that I am breathing life into a 5 year old thread.

I am a student now doing my solo cross-country work, and I have had multiple 3’fers and 4’fers to get the SR-20 to spark up. I’ll try this tomorrow.

Can anyone explain what happened yesterday to me, though?

I flew from KSFB-KOCF-KCTY-KGNV for a full stop. Nice flight, no problems. I gassed up, ate and preflighted to head back home the same way (45 min on the ground.) I went through a normal pre-flight check list and set up for a hot start. First try- 15 seconds and no joy. No surprise, it’s a hot start. Second try, 10 seconds and I got a little kick- so I added a bit of throttle… it started to catch then died. No problem, I’ve been here before. 3rd try- no movement on the prop. “Well S**T!” Just a humming sound (as in when the battery is dead in your car.) I’m a hell of a hike from home and start groaning. The volts were good, and I got a slight drop when I turned the key again, but no movement on the prop.

So, I called my school who got me on the horn with a very seasoned mechanic. He has me turn the mags off and go rock the prop. Not a hand-start, mind you, just up and down until I can hear a “squishing” sound. He then directs me to get back in the plane and try to start just as normal.

I hop back in and “poof” I get two more no-joy start attempts, but the prop is moving. On the third try, I turn the key and we’re back to just a hum with no prop movement.

I rock the prop again, this time I get back in and get about 5 revolutions on the prop before it stops turning while I am still turning the key.

One more time rocking the prop, but this time no prop turn with the key. They send a mechanic out with a new starter motor and another SR-20 for me to take back to KSFB.

He says it sounds like the starter is shot, we talk, I gas up my replacement and when I come back out to pre-flight after signing for the Avgas, he’s got the original plane running.

What the Hell?

When I got back to KSFB, he said it started right up for him. He even said he got it to start 5-6 more times with no problems once back at KSFB.

Now look… I AM a newbie, but I can’t see what I might have done wrong here. I mean I turn the key, the starter turns the prop… that’s the deal. I told the mechanic, who had a very distinct “you poor dumb bastard” look in his eyes that if that plane doesn’t do the same thing to someone else within 2 weeks, I’ll buy the beer.

Any idea on this?

22

When the engine catches, immediately pull the throttle all the way back. Then as the engine starts to die, push the throttle forward 1/4 of the way (about an inch or so). Then as the engine catches, pull it back again. Do this little throttle dance until the engine runs on its own.

Alex W. has a youtube video on starting. Find that. It isn’t hard to do once you have done it a thousand times… [:D]

23

I thought he was asking about why the prop didn’t turn when the starter was engaged. My guess would be bad starter relay, but it could be the starter itself. Doesn’t sound like the starter adapter.
Hot starting technique is another whole topic. Both the SR20s I owned had no problem starting hot.

via COPAme
Asus Nexus 7

24

In reading his story, he had several attempts where the starter worked, but the engine did not fire. By the third time, I think the battery had run down and/or the starter had overheated. The mechanic was able to start the engine (some time later) without replacing the starter - at least if I read that correctly.

Many new pilots seem to be unfamiliar with starting a 1950’s engine. Maybe all their experience is with electronic ignitions - just turn the key and the engine starts. If it does not start, just do it again… and again…

That’s the reason I posted the routine with the throttle. It is not intuitive to pull the throttle off when the engine starts.

25

I appreciate the input. You’re correct. I’m in my mid 30’s and have spent most (but not all) of my time with more modern engines in cars.

However, the prop failed to turn on the 3rd attempt. So two attempts with a kick on the second and then caput. I was reading good volts.

26

You, you burned the starter out. Anything more then 7 seconds and you are doing something wrong

27

*than