View Full Version : Hot starts W/out a starter

07-16-2006, 02:23 PM
For the starterless -What is the most successful procedure for starting an O320 hot, lets say 10 min, 1 hour.

07-16-2006, 02:42 PM
Call Wilbur, he is good at it, even when the prop is clocked wrong for hand proping. 8)

07-16-2006, 03:24 PM
The best method that worked 90% of the time with my friends 150 supercub was to leave the mixture alone (cut off position) Most of the time the 4th blade would get her going then quickly reach inthe cockpit and push the mix full rich. Sometimes on a cool day with a 45min. shut down it could be troublesome.

07-16-2006, 03:53 PM
The best luck I've had with any of the little four cylinder Lycs when warm is:

Throttle cracked, maybe 1/2 inch forward of the aft stop.

Mixture either full rich or idle cutoff, if it makes you happy. I don't think it makes much difference in these engines.

Crank it.

DO NOT, I repeat, DO NOT pump the throttle. Don't even think about moving it open an inch or so, then closing it back to 1/2 inch. These things flood REALLY easy when warm.

If flooded, mixture to idle cutoff, mags off, throttle wide open, and crank it, and crank it, and crank it, till you are absolutely certain that all vestiges of fuel are gone. Then crank it again.

Note that with wide open throttle, you really need to know that you don't have a hot mag, cause if it fires.....

Might want to tie it down good first as well, as during any hand propping exercise.

But, if you just don't throw any gas at it when warm, just crank it, it'll start almost every time in a couple throws.


07-16-2006, 04:12 PM
Our experience with my friends cub was if you pushed the mixture in it waould ALWAYS be too rich and an invitation to MUCH exercise.

SuperCub MD
07-16-2006, 05:09 PM
Sorry MTV, but I have to agree with Geezer on the mixture, and disagree with just about everything else you said, other than tying it down of you don't do this often...

When you shut down, shut down with the mixture, then turn the mags off. When you want to start again and it's still hot, leave the mixture at ICO, pump the throttle forward just a little to shoot some fuel in with the accelerator pump, then bring it back to idle then just cracked a little. Mags on(or left mag on if you have left only impulse), and it usually starts on the third blade. When it starts reach in and push the mixture in quickly so it keeps running, jump in and go. Trying to hot start with the mixture in will flood it every time.

Also, clearing a flooded engine at WOT pulling it through in the normal direction is stupid and dangerous even if you think you turned the mags off. If you screw up and flood it, mixture off, mags off, leave the throttle just cracked, not wide open, then pull it through BACKWARDS about 10 blades. This blows the fuel back out the carb instead of into the exhaust and is MUCH safer.

I prop the old 320 everyday and this is learned from experience, sweat and swearing, so take it for what it is worth.

07-16-2006, 05:14 PM
Whose airplane with a -320 are you propping? My little A-75 probably isn't much help, but I crack the throttle and mags hot -- no pre-flipping. Really helps to have someone in the plane to retard the throttle as soon as she fires difficult to do yourself with the cruiser door

Cajun Joe
07-16-2006, 05:52 PM
Help out a dumb coonass here.....

What is ICO and WOT???

(Also I sent a UPS package to me at your FBO address.
There is no fudge in there so save it for me.)


07-16-2006, 06:02 PM
My best guess is Idle Cut Off and Wide Open Throttle -- but those are just assumptions, and you know...

07-16-2006, 07:09 PM

bob turner
07-16-2006, 07:14 PM
I just can't resist this one! Airplane engines are funny little things, each with its own personality. I can start my IO360 hot, cold, or indifferent, but I cannot start my buddy's essentially identical engine. He can start his every time, but cannot start mine. These things are like _____.

07-16-2006, 07:50 PM

One month ago, I did hot starts twice a day, one time three times in one day, because I was in a plane with no starter. Started every time, mixture full rich, NO boost on the accelerator pump (TJ--you are right to an extent there, but you are pooling gas in the airbox, so if it backfires......).

As to turning it through backwards if flooded, IF your airplane has a vacuum pump, this procedure is NOT recommended, I'm told. I turn em forwards. If it fires, the plane is tied down, nothing bad happens. If it fires at all, and your hand is in the way, it'll bite. Just cause the throttle is wide open doesn't mean it'll start any different. And, by the way, I ALWAYS start from behind, ala seaplane style.

Do you have it tied down or not?? If it is, you may as well turn it forwards as backwards, though if you don't have a vacuum pump, it doesnt' make any difference I guess.

I would note, however, that I've seen one of these things run backwards almost as well as forwards, when propped that way. Dieseling, anyone?

I'll stick by my recommendations, thanks. They are tried and true, and have worked for a LONG time. I worked a Cub for a couple years that had no starter, and did a lot of stop and goes.

I am serious about not throwing ANY gas at the thing when hot. Do so, and you may as well go play pool for a couple hours, and let er cool off.


SuperCub MD
07-16-2006, 09:44 PM
Like I said, take it for what it is worth. But Geez, why would anyone put a vac pump on a Cub :D . I've always heard that turning backwards was no good for vac pumps, but have never actually seen or heard any real occurences of it doing any harm to them.

When clearing the engine turning it backwards just works better. Get the gas back in the intake where it belongs. When you turn it backwards the impulse couplings don't snap, and mags don't fire even if you screw up and leave the switch on, I say this is MUCH safer. WOT is really not necessary when clearing the engine, cracked throttle works just fine, and its just to easy to forget to pull the throttle back before you try starting again...... And when you open the throttle you are shooting more gas in the engine, making things worse.

I just have a personal rule that I never swing any prop in either direction unless the throttle is closed, or just slightly cracked. I will always error on the side of caution on this, and that ain't gonna change. And when I swing any prop, I treat it as if it were live, switch on, switch off, forwards, backwards, or what ever. **** happens, and I've unfortunately seen what can happen when **** happens, and I never want it to happen to me. That prop is nothing but a 6 foot long meat grinder, and I respect it as such. Like I said, I swing props every day, and if I'm overly cautious, so be it. I'd just advise anyone who doesn't swing props everyday to do the same.

I'm not trying to be offensive MTV, I'm sure you have propped enough planes and know what you are doing. I just hate seeing senseless accidents, and remember that those out there reading this stuff may not be as experienced.

PS, I'll look for your package Joe. I'll sign your name for it since it's sent to you, and I may have to open it and check for contraband...high airport security with the terrorists and all you know....And rrb is right on his definitions, he gets an A+.

07-16-2006, 09:59 PM
Looking back to the author of this post(Fourtysix 12) I am assuming a PA-12 is what you are propping. A 46 12 is what I fly now and would like to leave the starter on the shop shelf but feel the safety issue with a 12 is simply not worth it. The supercub and j-3 are reasonably safe to prop alone because you can hang onto the door opening with the left hand and prop from behind with the right hand. Unless your left arm falls off it is pretty difficult to get in trouble. With the standard door on the 12 safety becomes a serious matter unless you tie the tail or have a competent assitant. If you can get ahold of the Atlee Dodge tape "Hardcore" Mark Bills shows how to do the Supercub--My favorite cub tape; but I haven't seen the Props and Rocks one yet !!!!

SuperCub MD
07-16-2006, 10:06 PM
Geezer, The very first thing I would do to a nonelectric 12 or 5 if I had one is to install a seaplane door so it could be propped safely from behind. As a side bonus, it's much easier to get in and out of the things with a seaplane door.

Bill Rusk
07-16-2006, 10:41 PM
Personally I will never hand prop ANY engine with the throttle wide open. If it will not start with the throttle cracked then get it fixed. Every few months you can read about someone who was hurt or lost a plane propping with the throttle wide open. If the engine catches it will go to full RPM in a heartbeat and I am scared of being anywhere near an engine at 2500 RPM. To each his own. Furthermore, I will not do this with an inexperienced person in the cockpit. You can tell them to pull it closed when it catches, but it will startle them when it fires and goes to full RPM and they will push on the throttle. In the normal world you close things by pushing (drawers push to close, oven doors push to close, push on brakes, etc) so when they get scared they are going to revert to their normal habit patterns and push on that throttle not pull.

Be very careful.

Just my opinion.



07-16-2006, 10:46 PM
Yes MD I'd like the seaplane door. I really wanted a few more mods when I did the rebuild but simply got anxious to fly-- now that it is flying I can't stand to have it laid up much longer than an oil change !!!!Got a light starter and all is well for my needs and abilities....It took 15 years as it is --that door may have made it 16 !!!!!!!!!

07-16-2006, 10:51 PM
I must type as slow as I rebuild airplanes. Bill ' I agree with you on the open throttle business. ONLY time I'll do that is when an experienced pilot is at the controls. Geezer2

Cajun Joe
07-16-2006, 11:36 PM
open the package, enjoy then product (it's incredible) but
save the box ... I could never leave it in your care!!!!!

07-17-2006, 07:16 AM
I have an electric starter on my 12 so all is well there. The real reason behind the questions was a result of some training/flying with ACTS up in Palmer. Jay wanted us to be able to start the cubs by hand cold and hot. Cold was easy-one blade. But hot was another story. Never got any good at it. I've been proping my 12 (o235) and finding out its magic configuration. The 12 doesn't privide the hand hold for proping behind on the right side so I guess you could call it a tad more dangerous. But the 6 1/2 to 1 CR makes it nice. I find that I have to spin it pretty darn fast to get it to pop. Maybe a disadvantage to low compression ratios. Still studying though.

07-17-2006, 11:04 AM
The wife was wondering if in your shipped box you had "SLAP YA MAMA" Cajun Seasoning that she was running out of. But I found it on the internet and ordered her some!

07-17-2006, 12:56 PM

Your points on wide open throttle are well taken, and are excellent points.

As I said, if the plane is tied down properly, (and any time it's being hand propped, you'd BEST have the thing secured some way or other,) then forwards or back shouldn't hurt anything.

You are absolutely correct, though, that if you don't check your mags regularly to verify solid P leads, etc, turning the engine backwards does make more sense. I don't know if you'll see the results on a vacuum pump right away, but maybe. Wasn't my idea to install a vacuum pump, by the by :lol: .

I really wasn't arguing any of that stuff. You are correct, that turning the engine backwards is a safer way to clear a flooded engine. I've done both, but then got chewed out by a maintenance type. When I clear an engine, you can believe that the plane is tied down for a hurricane, and I am well out of the way. I always make it a point to verify p lead function every time I shut down, as well. We all should.

The point I intended to pursue is that I always prop it with a rich mixture, when doing a normal hot start. On some airplanes, like a 12, it's hard to get to the mixture control in time to catch an engine when it fires. I've never seen one that would flood IF you don't boost the throttle AT ALL.

As to propping from behind in a 12, I did it years ago, with a standard door, but with the mixture rich, and I had a handle installed on the right side boot cowl for balance. I'm kinda a clutz, and hate falling into props.

I just avoid propping from in front any way I can. That to me is truly scary.


SuperCub MD
07-17-2006, 02:27 PM
All very good points here MTV, and a good discussion of a potentially deadly activity. Hopefully anyone who reads this stuff who doesn't have a lot of propping experience (unfortunately that is probably most pilots these days), will at least come away with a respect for the seriousness of propping and it's dangers, it's all good.

I like the handle on the boot cowl idea on a plane with a forward opening door. When propping a 12, or champ type plane from behind, never grab inside the door frame with your left hand like you do on a Cub. When it starts, the prop wash slams the door on your fingers, you react by jerking your hand out and jumping forward towards the prop....bad deal.

Jeff, I built up a nonelectric 235 for a Super Cub some years ago, and I remember it being finicy to start. Its very easy to throw the blade on them, but I could prop a 320 more reliably, don't have a clue why this is. Id try to hot start it mixture out and throttle cracked, pull it about 4 blades. If you get nothing, add a little gas and try again. It's always easier to add gas a little at a time than flooding it and having to clear it. If you do this you may find the combination your engine likes. All these engines like to be coaxed into life a little differently. You may find a particular plane will only come to life if it is pointed East, you spin around 3 times between pulling each blade while singing the star spangled banner, and you are wearing a voodoo mask and your lucky socks. Carefully experiment with it, find out what it likes and give it what it needs. With the stock door you'll need someone inside to work the mixture. A trick I used to do was to open the cowl doors as soon as I shut down, this would get the heat off the engine a lot faster.

On my own 320 the first start of the day is always mixture in. A start after that can be made mixture in if it cools for a few hours. But if it's to hot with the mixture in, after a few blades it will kick back and run backward a few blades (bet that doesn't do vac pumps and a lot of other things any good either :wink: ). After it stops running backwards you get to pull the mixture, turn off the mags and do the clearing ritual.

Carey Gray
07-17-2006, 03:33 PM
On my 160, cold, I pump the throttle twice, pull 12 blades with the mixture rich, go mixture lean,mags hot, pull the prop and go flying.
Hot, I pump the throttle once, go mixture lean, mags hot, pull 3 blades and go flying.
That's if I have my lucky socks on. I always start with the mixture lean, just so I don't have to run to catch it. :oops:
I always treat the prop like it's there to kill me.

07-17-2006, 03:55 PM
Carey Gray wrote
I always treat the prop like it's there to kill me Propping has been a way of life for 30 some years and demands complete attention. I think of it as a big meat grinder and don't want to wind up being the hamburger. I recently delivered a j-3 to a new owner. When I got back home I got to worrying about the man. At 1AM I got out of bed and wrote him a two page letter about propping. Like flying itself, propping is rather unforgiving of errors.Much like my old instructor said of flying,"If it doesn't feel right -don't do it " !!!!

bob turner
07-17-2006, 04:47 PM
Geeezer is right - we ought to instruct in hand-propping with the usual caveats. No matter how experienced, I hear all kinds of stuff - one guy hollers "stick back, brakes set, throttles closed, make it hot!" Then he shoves on the outermost part of my beautiful wood prop just to make sure, at which point I release the brakes.

Two words suffice, as far as I am concerned: "Contact", and "Switchoff". And there should be a hysteriesis loop in there, so the switch is never on before the word Contact is shouted back, and always off prior to the cockpit acknowledgement of "switchoff".

Just my opinion.