39 Outerlimits twin 525s belt issues
 

Today went and ran the boat out of Baltimore marine center to Red-eye Dock bar to check it out and see some scenery. On the way back one of the serpentine belts snapped...it looked a little worn so Im not completely suprised but upon further inspection of the engine the lower left pulley on the 525 appeared to be stiff and wouldnt spin...I think it is the coolant pump pulley but I am not entirely sure...

Questions are...

#1 What is the lower left pulley on the 525?

#2 With the belt off should it spin freely?

#3 If so, what needs to be replaced.

thanks for all the help!

That pulley you are asking about is the raw water pump. You will see two hoses off the back side. Inside that black cap with the hoses, is the impeller. It will have resistance provided your impeller is in good shape. It will be easier to turn one way than the other because of the direction of the rubber impeller. Buy a new belt and do it yourself. Loosen the tensioner pully first before trying to install the new belt. It's easy. The tensioner has a 5/8 head and an inner 5/16 head to adjust the belt tension. Loosen the 5/8 then turn the 5/16, Do the reverse to tighten. I found it easiest to use a 5/16 socket and a 5/8 open end to adjust and tighten. Make sure the belt grooves are aligned on the appropiate pulleys.

Good Luck

i would open up the pump and see what you find.

x2