POH also states the performance factors etc, and we all know we have refined techniques that allow us to beat those figures the vast majority of the time. Some things that you might understand would be rolling a float etc. I have seen many posts by yourself where you have stated that you figured out techniques over the years to get a plane off the water, start easier etc. To now just say that the POH is the end all and the only / best way to start an engine seems ludicrous at best.
As far as the last statement, if I have impulse couplings on both mags (which I do) why in the bad word would I not use twice the amount of spark power to light the fire? It starts easier and better with both mags on the starter, so why not when propping it?
Here's a question for you: What does rolling a float out of the water as a technique have to do with starting an engine? Completely different subjects, one of which MAY have recommendations in POH, others may not.
Secondly, the POH data is derived to best serve an "average" pilot, assuming that pilot is basically qualified and trained to operate the plane. So, of course, you MAY be able to derive slightly better fuel flows, performance data, etc.
When it comes to starting an engine, the manufacturer offers what the test pilots found to be the safest, and perhaps best way to start an engine. That information goes into the POH.....IF your airplane has one. Many belonging to members of this forum don't have a POH.
And your comment that I've stated in past "start easier" is more than a little disingenuous, to say the least. I have on several occasions on this forum, advocated using the guidance given in the Cessna 185/206 POH on starting. If I've offered different, I THINK (hope) it was reference to an airplane without a POH.
In any case, my latest comments on this thread have to do with an airplane which came equipped with a POH: the Piper PA 28, which I have a fair bit of familiarity with. For many years, I have advocated consulting the POH (IF THERE IS ONE) for recommendations to start an airplane.
A Super Cub or a PA-12 was never provided with a POH, so in the context of the initial post, it's irrelevant, and I specified the model of aircraft I was discussing in that post.....a PA-28. While the Super Cub and Cruiser both came with "operators manuals" or "Owners manuals", the information there is MAYBE not so thorough as that offered in a POH, or maybe it is. I'd bet that an owners manual for a cub, if it gives starting suggestions, suggests you use the primer, if installed.
I've posted on here to use the Manufacturer's recommended procedure in a Cessna 185 and a 206, both of which I've started regularly in almost any situation you can imagine, from plus 100 degrees to -40 degrees, and up to 7500 feet msl or so. That would be to read the POH, and use the recommended procedures there. And, oh, boy are there a LOT of folks who have "better ideas" on how to start those engines. The POH data has worked for me. If what they are doing works for them....so be it. Not my problem. But, that doesn't mean its right.
BUT, this discussion was about starting a small, carbureted Lycoming engine. Those engines were designed to be started with a primer....why else would the manufacturer install primer fittings on their cylinders?
Good on you for having impulse on both mags. Most don't. And, frankly, the average pilot simply doesn't know if his engine has dual impulse couplings or not. So, my recommendation was, unless you KNOW your engine has dual impulse couplings, ALWAYS start on left mag only. Sorry, i should have added that wording. As I pointed out, even if you do have dual impulse mags, there is no harm at all in starting on left mag only.
So, here's a question for you: You walk up to a Cub you've never flown. How do YOU know whether it has dual impulse or one? This is a question for pilots, most of the folks on here are pilots, not mechanics. THAT was my point: If you don't know for sure, start on the left only. Sorry if I confused you.
And, lest someone else chimes in with "Well, my airplane has an "Off/Left/Right/Both/Start" positions on the key starter switch, so I can't select left mag only for start. If that's the case, that switch is set up to turn the RIGHT mag OFF when you select the "Start" position. When you release the switch from the "start" position, it automatically re-connects to "Both". So, in those cases, the switch is selecting the appropriate mag for you. OR, both your mags are equipped with an impulse coupling.
But, why would a manufacturer actually install an ignition switch that turns off one magneto for start? Maybe because most of these engines are DESIGNED to start on left mag??
And, finally, an FYI: Not many floatplanes I've flown came equipped with a POH float supplement that gave a lot of detailed information on how to get airborne. There's a lot of information that's just not written down in those things, frankly. And, many of the planes I flew on floats didn't have a POH or a float supplement.
Finally, I'm not suggesting that the POH (if there IS one) offers the ONLY way to do things. Those techniques and procedures offered therin, however, have been tested by the manufacturer to work reliably under most circumstances. So, I'll start with the POH, and go from there.
So far, the POHs I'm familiar with do a great job telling you how to start the engine.
As always your mileage may vary.
MTV