Reading the comments and researching the subject, I decided and ended up with this particular pump. Its use is purely amateur, for pumping water from a rainwater cistern with a maximum height of 4 1/2 meters.

About the pump: the frame is quite stable and well-made. The engine is two-stroke, with some noise and vibrations, but since I use it in the field, I don't mind. The fuel tank needs attention as its plastic is not of the highest quality (though it does have some protection), and its orange plastic cover is not the best (it might dry out and deteriorate over time). In general, it needs protection from weather conditions and NO mistreatment during work. The pump body is made from some metal alloy (aluminum?), and it seems it does not like rough handling.

Of course, overall it is a lightweight construction + you get what you pay for, as someone might say.

About its operation: IMPRESSIVE that when it came out of the box, it started ON THE FIRST pull!!! I didn't expect that... And every time it starts on the first try!! Of course, I always use 100-octane gasoline with the correct oil mix in all my two-stroke tools (chainsaws, tillers, etc.). Try it, and you will see a difference in how the tool works! ALSO, change the spark plug for something better quality, as the existing one is a no-name Chinese one.

I connected a 1 1/2 inch hose to it, as the manufacturer says, for both intake and output, with the output at 11 meters. At about half throttle, it delivers water with quite a bit of pressure and volume...!! In 5 timed minutes, it filled a pallet tank in my pickup. Since I don't need more pressure or volume, I find it extremely satisfactory for the jobs I want. I DON'T WANT to pump huge amounts or irrigate vast areas; as I said, it is for purely amateur use! In terms of height, I believe it can lift water even to the first floor from ground level. I operated it for at most 20 minutes continuously at half throttle, as I didn't need anything more. And I think it's not meant for endless hours of continuous operation. In that time, it must have used about half a tank, around 350-400 ml.

Another important thing: for it to immediately draw water, you need to fill it well at the filling mouth on the pump body + fill the intake hose with water, and as soon as you rev it up, throw the hose into the water you want to draw! + TIGHTEN WELL the fittings on both intake and output so there are no gaps!! It will immediately draw water!!

Overall: for purely amateur use, to pump water without getting tired, to water a small field with breaks in between, and with proper care and protection, it is a good little tool that won't disappoint you. It will do the job, but it needs care and not mistreatment.

useless product. it was a struggle to get the water up, I tried a clamp, I tried a check valve, nothing worked properly, I mean you have to fight for 2 hours in the sun in the field to catch the water. after 10 times of working poorly, it was dying and the motor would shut off when trying to catch the water. STAY AWAY.

It lasted exactly 3 days, wasted money, burns a lot even though it provides good pressure, not worth it, replaced with a 4-year-old one

Easy start. Satisfactory suction and propulsion. Fuel consumption up to half a tank is satisfactory, then it rises sharply. Very good value for money. Easy to transport.

Very good, well-made, doesn't seem like a cheap pump.
Starts immediately, relatively quiet for a two-stroke. When the throttle is fully open, which is where it delivers maximum flow, it sounds a bit louder but not annoyingly so.
After testing it on a well approximately 7 meters deep, it provides a good water flow. Since it's not self-priming, you need to move the hose up and down to get it to draw water, only at the beginning. After trying it with a 1 and 1 1/2-inch hose, I concluded that it performs better with a larger flow and pressure at the 1 1/2-inch (which is both the outlet and the suction).
I used a 1 and 1 1/2-inch fire hose and fire nozzles. It had enough pressure, the nozzles sprayed water quite far with pressure. Of course, I didn't push it too hard as the pressure gauge from the pump's outlet was about 4 meters.