Wow, a less than a 150 mph stalking 3.0L. I've heard of em. Just didn't know of anyone with one
I know 150 isn't speed, but was it rpm? Temp? and I assume it's stalling.
Assuming rpm and it stalls below 750 may just need a full tuneup.
But untill you explain some things and give details of year etc. don't expect much help.
150 = 1500RPM
stalking= stalling
everybody has to start somewhere-
visually check plgs-,wires, ignition- anything look worn out or broke/ unpluged ?
look for rope / fishing line wrapped around prop ?
make sure fuel & filter are good.
check oil level-does it look milky or clean?
other than that ask around for good shop to take it to.
good luck to you-joe