that round piece that the fule line goes into then out is in the pictures in my factory manual but they dont mention it? I cleaned it off this morning it has arrows on it and says mikuni? As far as stalling pretty much anything at full stick will slowly stall it. a full stick zero turn will stop it dead. inclines it will slowly die out. I'm pretty good at keeping it going by using the sticks(which is why it has been this way for so long). as for the rpms I was just wondering if I wasn't running it high enough. Since it has been doing the stalling thing since I got it, had me wondering if it wasn't set right? had an old dynahoe 190b that I was running too low till I got the manualand realized I was at 1700-1800 and it should have been 2800 minimum. I think I wrote it earlier the best way to describe it is if you were to take a standard truck and drive in creeper without touching the throttle or clutch and tried to roll up an incline. happens faster loaded or any kind of a turn involving opposite rotation of the tires.That round part is possibly a one way valve, its not factory.
How hard do you need to push the machine before it stalls out?
As already stated, you need a tacho to know what the engine is doing, i have a cheap Ebay one that uses reflective tape and a laser beam. Just put the tape on the crank pulley, easy. The RPM should be factory set, generally does not need changing.