It sounds like you are not priming the engines.  In my experience every engine needs to be primed (if you're starting it cold), and each engine -- even if it's the same model as another one in your collection -- needs a different amount of prime to be happy.

On a different note, for this issue what's important isn't the location of the pickup, it's the level at which the fuel is coming into contact with the air.  In a standard (not uniflow) tank this will be at the top of the fuel load.  In a uniflow tank with an empty uniflow tube this will be the level of the uniflow tube.

If your metal tank is uniflow, then if anything it should feed less readily just sitting on the ground than your plastic clunk tanks.

Anything that puts fuel in the engine before you start it is priming.  So -- both A and B.

Depending on an engine's timing, putting your finger over the venturi may or may not successfully prime the engine.  A mildly timed engine like a Tower 40, 46LA, 40FP, etc., will self-prime this way.  An engine with more aggressive intake timing (meaning one that closes later) will draw fuel part way out of the tank and then spit it back again before the intake closes.

As an example, when I prime my Magnum 36, I cover the venturi, rotate the prop to the magic spot, uncover the venturi for half a turn, then repeat.  If I don't do this I get the whole "spit it back" thing.

I'm pretty sure that an EVO36 has very mild intake timing.  I don't know about the Jett60 -- I'm too cheap to own such a nice engine.  Perhaps someone familiar with it will chime in.  What's the engine on the last plane?

If you can see the fuel in the tube (it may be worth taking the cowl off just to do the experiment), on an aggressively timed engine you'll see the "spit back", which is what tells you how to time the priming thumb with the propeller.  But then, priming with a known amount of fuel from a syringe will work just fine.

"As an example, when I prime my Magnum 36, I cover the venturi, rotate the prop to the magic spot, uncover the venturi for half a turn, then repeat.  If I don't do this I get the whole 'spit it back' thing."

Since I put a lot of flights on that very same Magnum .36, I'll report that I didn't ever do that, and had several strings of 1-flip starts and a couple of those without the battery. I merely clamped a thumb over the venturi/restrictor and pulled it through some magic number of pulls, then flipped the prop quickly through a similar number to distribute the fuel, applied battery and signaled the judges.

I am now wondering which method would be more consistent, and think it would be mine, at least for that engine. I could hear the "blubbery" or "juicy" sound in the muffler, which I do not hear with a tuned pipe...which I have a lot more trouble with the engine being too dry. My usual abusive method is to put my LH index finger over the venturi and hold it while I use the electric finger. When the engine starts firing, I remove said LH index finger.

It isn't wise to finger flip a CF prop unless you can "spinner flip", which obviously, I can't at this point. I'm pretty shy about flooding the damned things (PA .51 and AAC .46VF). Perhaps I will just spend some time trying to hit that "magically juicy" point!  Steve 

...... why the squirting directly into venturis is needed?

Without this squirt both engines combustion chambers stay apparently dry because there is no kick from the glow plug when the prop is slowly moved by hand.

Are we talking here some general rule for the side mounted engines or, accidentally, the engines in Toucan (Magnum Pro45) and RToucan (Jett60) are "weird".

Thanks,
M

My bet is that you are giving enough prime but that it is not reaching the combustion chamber. It is pooling in the lower crankcase because it can't easily get out with the transfer ports being in that orientation. So you have to over prime to compensate.

Try your normal start procedure with the model inverted or simply head down - any different?

A solution may be to install a Team Race style priming tube against the exhaust port that wets the piston side through a CLOSED exhaust port.
That way you are only priming where its needed and you will never flood the engine.

Good luck.

P.S. Check your fuel tube route also, I have seen so crazy plumbing methods used before - a pic would help.