Is there an easy way to start an LA 46 with head down (upside down) without flipping the plane over?  When I draw fuel into the engine with 4 or 5 flips and then flipping 5 times before connecting the battery, it floods so tight that I can't even flip it.  That is my procedure with side mounted engines on profile planes.

Please disregard this post. Through search, I found that I asked this question five years ago and got all the good responses I need.  Thanks anyway!

Quote from: Allen Eshleman on September 06, 2025, 09:17:33 AM
Please disregard this post. Through search, I found that I asked this question five years ago and got all the good responses I need.  Thanks anyway!

    Are you getting old like the rest of us Allen!!??  Memory is one of the first things to go but I can't remember what the other things were!
    And just to add, try sneaking up on how much to choke it. One choke , then flip, the two chokes, etc. Atmospheric conditions and temperature affect this also.
  Type at you later, if you remind me!
    Dan McEntee

Thanks Dan.  I want to fly that again.  I don't remember why I stopped flying it.  I only know that it's very nose heavy. So, I'm balancing it again.  I did fly it once the other day. Yes, I am somewhat forgetful.  I found that post and it's like what you said.

I rather prefer to start an inverted engine with the airplane turned over...for safety reasons...after I fumbled an ignitor into the prop of my OS .46VF. Scrapped the prop and ignitor, but at least it was a DuBro with removeable battery, so that was salvaged. Of course, this won't work if you're using most stooges. 

A safe alternative is to wire the airplane up with a micro phone jack and use a wad 3 or 4  1.5 volt alkaline D cells wired in parallel. I haven't done that, but Alan Resinger did before he went with electrons. Steve

Quote from: Allen Eshleman on September 06, 2025, 06:57:16 AM
Is there an easy way to start an LA 46 with head down (upside down) without flipping the plane over?  When I draw fuel into the engine with 4 or 5 flips and then flipping 5 times before connecting the battery, it floods so tight that I can't even flip it.  That is my procedure with side mounted engines on profile planes.

With inverted engines there is ALWAYS the danger of a hydraulic lock.  Yes, it CAN be done.  But you need to make sure it turns over OK before any serious flipping gones on.

The physics of choking an inverted engine is the problem. Choke it with the cylinder head down and the fuel fills the venturi and runs out on the ground when you remove your thumb. The natural reaction is to choke it much more, leading to hydro-lock. Why not choke the engine with the cylinder head UP, do the flippity-flip stuff, then turn the plane back (wheels down) to actually start? Aside from that, practice helps a TON. It IS possible.

Most piped engine users "burp" their engine before hooking up their lines, which isn't a bad procedure for any engine. Personally, I seldom did that, with several piped engines. But I had a love affair with the Magnum XLS .36 on my Twister. I had as many as 13 one-flip starts with that engine, and several strings of 8 > 10. It also started twice without the glow ignitor, and both on official flights...it just wanted to run! Figured it had 20 gallons of 10-22 through it and still a 1-flip start engine. Wowzir!  Steve
 

Quote from: Steve Helmick on September 18, 2025, 01:28:48 PM
The physics of choking an inverted engine is the problem. Choke it with the cylinder head down and the fuel fills the venturi and runs out on the ground when you remove your thumb. The natural reaction is to choke it much more, leading to hydro-lock. Why not choke the engine with the cylinder head UP, do the flippity-flip stuff, then turn the plane back (wheels down) to actually start? Aside from that, practice helps a TON. It IS possible.

  There's no real need to flip it upside down, it's a matter of technique to start it normally and A LOT safer than having to flip over an airplane with the engine running. Some of the rituals for that are almost comically dangerous. Watch Billy (a classic upside-downer), Bobby, and Bob McDonald do it, it looks completely natural (albeit unnecessary). Hint - the launcher needs to be on the *outside* of the circle, so when it is flipped over, they are in the right position to launch.

QuoteMost piped engine users "burp" their engine before hooking up their lines, which isn't a bad procedure for any engine. Personally, I seldom did that, with several piped engines.

     That is a sort of different problem, the oil in th e pipe usually migrates down into the cylinder when it is held nose-down, and can lock it or at least make it so loaded with oil that it's hard to wash it out otherwise without getting too much fuel. Some engines are much worse than others, the 40/46VF being the worst case I ever ran, I didn't even bother to try to get the oil out normally, I took out the glow plug entirely, drained the oil, and primed it for the burp, then put the plug back in. The RO-Jett, you at least have a chance, but I don't like wasting people's time when it doesn't work and I don't want to flip the airplane over with a full tank of fuel.

    Brett

What I would do is prop it through enough to make sure it's not locked and it needs a prime. Then turn the prop backwards until you feel a little compression, this will close the intake valve. Take a small squeeze bottle and mist some fuel in the venturi then wait for most of it to run out. Should start right up.

MM

Usually , the first start of the day , pays to do it ' plug up ' as it were .

The getting it to burp on a prime , a few times , the fueling it , usually works .

something like 4 drops down intake , flick six times , then backflip six , Fuel Up , place on ground , push fuel to NVA , Prop Fwd , backflip . S'running .

IF youset the PROP dead level , FLAT - against compression ( so it wont snap in a inverted landing ) its in the RIGHT POSSITION , to Flick the L E down -

So the backfire starts it . itself .
We wont mention sharp prop trailing edges & cut fingers , Flicking em Fwd .

With the piped planes, it really helped to get the helper to carry the model with the nose up, tail down. I never had a problem with the .46VF or PA .51 filling with oil or hydro-locking, maybe because of that? I think most or all of the pipe users burp their engine with the glowplug up, don't they?

Our Sunday morning crew mostly likes to start the engine glowplug skyward, but we're having trouble training some to wait for the signal to point the nose up. Maybe some D.I. linguistics would work. At least, it helps to heat the engine up quickly, because a lot like to set the NV before it's warm. Inadvertant flap tweeks and unnecessary bending of the leadouts while retreiving are also problems. Steve

Quote from: Allen Eshleman on September 06, 2025, 09:17:33 AM
Please disregard this post. Through search, I found that I asked this question five years ago and got all the good responses I need.  Thanks anyway!

Allen, can you remember where that thread was?  I am going through this issue right now with the same engine. i think i made some progress by not choking it more than 3 turns. I also dislike the wheels up starting method for all the reasons Brett mentioned plus having the exhaust from  the muffler spewing straight into the face of whoever is holding it.
Thanks,

Kevin

The 'trick' is really not to flood it with either fuel or left over oil.   Even old Fox .35's are best 'burped' with a few squirts down the venturi  before filling the tank a couple times to clear out residual oil then will start with a choke or two.   It will take some experience with each engine to understand how much to choke or prime it.

Quote from: Kevin K on October 10, 2025, 07:16:17 PM
Allen, can you remember where that thread was? 

Among very many:

https://stunthanger.com/smf/open-forum/starting-inverted-engines-and-a-stooge-dilema/msg395239/#msg395239

Brett

You might occasionally come across an engine that for whatever reason just doesn't start well inverted.   I have two that won't fire inverted no matter what I try..  A Merco .40 Blackstreak and one particular OS .35S.   Turn them upright and they fire off first flip.   My Foxes will go inverted pretty well IF I turn them over and prime them well first,  them set them on the wheels to start.   About have to since I can't get to the venturi buried deep in the cowlings with extension shafts.

Dave

Looking at the FP 60 , on sceptre flight . The HEAD has a lump at the PLUG .

so as its raised above the chamber , inverted . to keep the plug dry , rather than flooded - even if the cylinder heads  awash .

The moral of this story , is - if your plug floods out - try a 4 stroke plug - with the raised center protrusion .

Obviously you want the plug orange and bright , at the element . If you need a damp motor to kick off / bump start .

Quote from: Dave_Trible on October 12, 2025, 04:19:09 PM
You might occasionally come across an engine that for whatever reason just doesn't start well inverted.   I have two that won't fire inverted no matter what I try..  A Merco .40 Blackstreak and one particular OS .35S.   Turn them upright and they fire off first flip.   My Foxes will go inverted pretty well IF I turn them over and prime them well first,  them set them on the wheels to start.   About have to since I can't get to the venturi buried deep in the cowlings with extension shafts.

Dave

As long as you *can* get access to the venturi, the Fox is about the easiest engine of all to start inverted, hot or cold.

Brett

Quote from: Allen Eshleman on September 06, 2025, 06:57:16 AMIs there an easy way to start an LA 46 with head down (upside down) without flipping the plane over?  When I draw fuel into the engine with 4 or 5 flips and then flipping 5 times before connecting the battery, it floods so tight that I can't even flip it.  That is my procedure with side mounted engines on profile planes.

Maybe I'm just lucky but both an LA 46 (Vector 40) and an Enya SS 35 EX (Nobler ARF) have started w/ one flip when I do the following:

-Tank filled, but fuel supply tubing and engine not primed (dry from previous flight)
-Needle set to the approximate turns where it needs to be for normal flight (If it is too far open it will easily flood during priming)
-4 aggressive prime flips w/ finger over the venturi
-Then like 15-20 aggressive flips to really get the fuel mixed up in the engine
-Apply glow power
-Finger flip to start

(BTW, same basic procedure I use for profile-mounted engines)

For me the trick is to really flip a 'bunch' of times after the initial finger prime.

Above has worked for me 'so far'!  I flew my Vector this past week. Started 1 flip every time.

Colin

Quote from: Colin McRae on April 29, 2026, 02:22:03 PMMaybe I'm just lucky but both an LA 46 (Vector 40) and an Enya SS 35 EX (Nobler ARF) have started w/ one flip when I do the following:

-Tank filled, but fuel supply tubing and engine not primed (dry from previous flight)
-Needle set to the approximate turns where it needs to be for normal flight (If it is too far open it will easily flood during priming)
-4 aggressive prime flips w/ finger over the venturi
-Then like 15-20 aggressive flips to really get the fuel mixed up in the engine
-Apply glow power
-Finger flip to start

(BTW, same basic procedure I use for profile-mounted engines)

For me the trick is to really flip a 'bunch' of times after the initial finger prime.

Above has worked for me 'so far'!  I flew my Vector this past week. Started 1 flip every time.

Colin

This is pretty standard practice.  The flipping is vaporizing the fuel mixture making ready for easy ignition.  Be careful when attaching the battery.  I COULD fire off on it's own.

Dave

Quote from: Dave_Trible on April 30, 2026, 08:28:17 AMThis is pretty standard practice.  The flipping is vaporizing the fuel mixture making ready for easy ignition.  Be careful when attaching the battery.  I COULD fire off on it's own.

Dave

Allen mentioned he flipped the prop 5x after priming. I'm guessing that was not enough.

And I always hold the prop when attaching the glow power.

Colin

Quote from: Colin McRae on April 30, 2026, 08:41:48 AMAllen mentioned he flipped the prop 5x after priming. I'm guessing that was not enough.

And I always hold the prop when attaching the glow power.

Colin

Well priming was the issue.  Just the thumb over the venturi for one or two turns is usually plenty.  Any more and it's flooded.   Squirting fuel into the engine is no-no unless you can't get to the venturi to choke.  I've seen some prime, then choke, then cuss at the engine.   Modern engines drown so much easier than the old ones.  Because of better piston fits and extra boost ports they have a much better fuel draw so more care has to be taken not to flood them.  It's better to try starting a little dry then add a choke than the other way around. If it DOES hydrolock DO NOT try to force it over.  You may well bend the rod.  Instead hold the airplane straight up and gently turn the engine over a few times until the excess clears.

Dave