Outdoor Power Equipment and Small Engines - JD STX 36 yellow deck stahl problem

When I engage the mower blades the mower slowly stahls out after a few minutes of use,does anyone have any ideas I can try to fix this problem?

Did you do any work on it receintly??? As in replacing a belt??? Have you looked @ the spindle bearings,pulleys, idlers or even the belt routing yet??? A bearing may be siezing up & is overloading the engine or the belt may have been installed wrong or jumped to the wrong side of a belt guide... All assuming there are no carb or other engine issues.... Maybe a little more info would help as funny noises, engine running well, not surging etc??? Even the engine numbers would help the pros... Roger

STX 36?
JD site lists a 30 and 38...?
In addition to what hopkins suggested,
If you disengage the blades will it continue to run normally?
A few minutes is a rather long time, is it the same amount of time or close always, or does it vary...?
Electric PTO?
Does it bog down and die or quit as if you turned the key off?

I apologize it's a STX 38,I have had repair work done recently but not to the belts or pulleys,just oil and spark plug changed, new solenoid,starter and battery installed,I will check the belts.The engine is a Kohler 12.5 ohv,thank you Roger.The mower will continue to run normal when I disengage the blades,it is an electric PTO.It does die down as if I am turning the key off,the time in which it stahls does vary,thank you BFHFfixit.

I would suspect the wires to your PTO. There should be only two so you could inspect them for wearing or chaffing someplace that they may be grounding out.

Do you have to boost it to start it?? even with the new battery??? I ask because if the battery &/or charging system isn't up to the job & you have a battery ignition system, the PTO could draw the battery low enough so it wouldn't run the ignition... Just a thought & to be honest,,, I'm thinking it would have a mag system???/ Roger

I was just about to suggest the same thing as hopkinsr2. It probably has a fuel shutoff solenoid that would shut down the engine if there wasn't enough voltage to hold it open.

Good point Cheese.... I always forget about the fuel solonoids ,,,They as well need 12 volts to operate.. For some reason I don't see a lot of riders here,,, I'll remember from now on tho... Thanks.... Roger