Sorry, I mixed yours up with another
Don't know if it has a MEFI, 555 ECM or PCM but... if I had a serial number ...
The fuel pump is turned ON/OFF by the ECM applying a ground to one side of the relay coil. Trun key ON, energizes Main Power Relay (MPR) should hear a beep then fuel pump turns...
Got that on the first post, but without knowing what "motor" your working on we cannot help
I'm pretty sure its not a Briggs and Stratton but other then that I have no clue. Might be a Merc, VP, Ilmor, carb, efi, mpi :unsure:
ok, thanks
Here is what we know, and correct if I'm in error
With clear kinked hose in place the motor stays cool
With non-kinkied hose it over heats
The crossover is part intake and part thermostat housing (TH).
Prior to a crossover water moves from the raw water pump to TH and passes...
Not as much with fresh. If something is clogged then less water
A good test is with a short piece of clear hose. Test must be done with boat in the water, a hose will not provide enough flow
Get a short piece of clear hose from the local hardware store, same size is raw water pump hose. Get...
This being a Mercury sport jet I moved it to the Mercury/Mercruiser section. It will get more views.
Never messed with one. I'm looking at the parts and not seeing anything that would tell me what might be the issue. Intake area maybe?
Don't know of a mechanic to recommend in FL
Without hands on, it might be in the crossover. Reason to mention that is motor stays cool when a kinked hose is installed. As before the only reason I can see for the m to i hose is for draining during winterization. There should be no water...
Welcome
First are you sure it's getting hot, as in has it been checked with a IR temp gun on the thermostat housing?
If it is getting hot check the hose connection on the drive that connects to the hose to the raw water pump. Many times they get clogged up
Might need another pressure switch, most should cycle between 20 to 40 psi
https://www.xylem.com/siteassets/brand/jabsco/resources/manual/31620-water-pressure-pump.pdf
Do you have a scanner, and was there any codes?
Might help to narrow it down
Assume they are both mechanical shift and not DTS
I'm looking at Merc just to maybe get some clues if they did something different
Another thought, wonder if Bob at OBD Diagnostics might help. He does repair and...
Was thinking you might know if there were any pin out differences and just mention those. OP would know his serial number but probably not the other harness. Looks like way more complex I guess, each serial number could be different
