1980'ish black max 150 losing all power after running for 30 minutes

[Chris1956]

Larger motors like your V6 can benefit from a direct fuel line connection to the fuel pump. Those quick disconnects can restrict fuel flow or allow air into the fuel line. I recommend you get a 3/8" brass hose barb to hose barb and install it with two clamps, replacing the quick connect.

You should remove the anti siphon valve in the permanent fuel tank, for testing. Once you get the motor working, you can re install it.

 

[Dukedog]

go to tha auto store.. buy tha cheapest electric fuel pump (3 ta 7 lb output) for a carbed car motor.. connect it as close to tha tank as possible.. it can jus be hangin' free for now.. supply side of pump go straight (no bulb) to tha carb bib that feeds them all.. plug off all lines goin to and commin' from mech pump.. connect power to tha new pump to any purple (its a switched by key on/off) wire, anywhere ya find it.. ground tha other side of tha pump anywhere possible... go for a ride.......... if it solves ya problem ya gotta decision ta make.. leave it or fix tha mech pump with new bulb also...

jus in case make sure tha carb floats are right.... use all new fuel line/clamps.