Engine dies when I step on the gas
but my question is why would it only stall in "Drive"? when its in "Park" and I rev the engine, she revs up just fine without a hiccup.
Like I said; Load-related.
This is very often an ignition problem, but could be low cylinder pressure, which could be one of maybe three reasons; design, age/wear, or tappet adjustment.
But the simplest and most common causes of all are; a misadjusted or faulty A-pump/A-pump circuit, or a too cold intake/engine. Either of which could be aggravated by a low intake vacuum reading, and retarded timing. A cold engine just makes diagnostics between very hard and impossible. A cold engine requires more horsepower to run, at a time where there is almost no horsepower being produced. This is another reason that the Idle-rpm has to be increased on a cold engine. And if the ignition timing-advance system has failed, that is a third strike against the cold engine.
The warmed up engine in Neutral/Park, will idle or can be adjusted to idle, on just about any timing, especially on a long stroker like the 225, cuz it has a lot of flywheel effect. And in fact, the warmed-up engine actually wants way more timing than the factory allows. Unfortunately, with a distributor timing system, the amount of timing at any other place but the Power-Timing, has to be reduced by the constraints of the system, and the ability of the engine to absorb it, without detonating. So if the timing between the Stall rpm and say 3600rpm has to be a slope with a certain gradient, and that gradient leads to an idle-timing of 5* After TDC, then that is what has to be.
But when you put it into gear, and the TC drags the rpm down, now a bad tune will make itself known because, the rpm can no longer free rev, which could have been hiding a multitude of tuning failures.
Tuning your slanty sortof parallels tuning a lawnmower. You could have that hummer working so fine in the garage, but it won't cut grass worth spit, when the blade slows down. There may be absolutely nothing physically wrong with that mower, and you might tear your hair out looking for the why of it. This is a load-related problem, and it's usually in the tune . But you gotta start with the basics to rule physical problems out.
That mower will start with as little as 30 psi compression. But it won't make spit for power on just 30psi. So that is why we start with a compression test. And this very often leads to a valve adjustment. And then unless it has an auto-decompressor, which thing I hate, you can tell what's what. Many push mowers with starter ropes, only make 90psi..... because you know, ladies can't pull-start them with much more than that. So if you get that push-mower to put out 90psi, you can bet there is nothing wrong with that part of it.
But hang on most push mowers have horizontal intakes just like the slanty, so you gotta prove that the piston is also sucking. And don't forget, the pushmower does not have a centrifugal timing advance system, so if she's down on power but has adequate cylinder pressure, then the next logical thing to check is the flywheel key, which sets the basic multi-purpose, all-inclusive, timing. And after that, you gotta check for a plugged muffler. and then the blades. Dull blades will drag the rpm down, just like the TC in your car. When the rpm drops, the two-circuit lawnmower carb gives up. It was not designed to run anywhere but idle and more or less wide open. And the governor sees to that. There is no A-pump, no power valve, no intermediate circuit, and sometimes there is not even a decent float chamber.So whoever is doing the tuning, has to get the settings just right.
The only basic difference between a push-mower and your slanty is five more cylinders and a level of sophistication that allows it to run under load at various other rpms than idle and WOT.
Ok it's getting white outside, so I better go install my studded tires.
