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RPM and getting into gear over winter break

3

3-legged-dog

Contributing Member
03, 25' crownline, 350 mag, bravo iii, 2 questions, this is my spring check up. drive is currently off getting painted and cleaned up. Boat is in my drive way. boat fired up and running first turn of the key not bad for winter break.

1st question, with drive off, engine running, i shift into forward, i shift into reverse, back to neutral. i dont hear anything engaging at the engine. i dont remember if i need the drive on to hear the engine switch gears and engage the clutch.

2nd question, i have no RPMs registering on the gauge at the helm, in idle or when throttling up, i have oil pressure and temperature gauges working.

thoughts, thanks in advance.
 
If this is a non efi motor and no tachometer reading,

on back of tachometer is a selector switch, 4 cyl, 6 cyl, and 8 cyl.

use small flat bladed screwdriver and switch back and forth from one setting back to V8 setting and try again.

if that does not work, shake harness under dash where grey tach wire goes from tach and check connector connections and/or check main engine wire harness connector (large black at engine) twists it a little and/or remove and reinstall and see if tach come back to life.
 
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3-legged-dog said:
03, 25' crownline, 350 mag, Bravo III, 2 questions, this is my spring check up. drive is currently off getting painted and cleaned up. Boat is in my drive way. engine fired up and running first turn of the key not bad for winter break.
Question: with the drive removed, how did you supply cooling water to the engine located BIII seawater pump?
If this seawater pump was operated without cooling water, it may have become damaged!

1st question, with drive off, engine running, i shift into forward, i shift into reverse, back to neutral. i dont hear anything engaging at the engine. i dont remember if i need the drive on to hear the engine switch gears and engage the clutch.
As Bt Doctur suggested.....no drive/no engagement.
The BIII transmission (of which houses the the 3 primary gears and the cone clutch) must be in place for any transmission of power!

2nd question, i have no RPM registering on the gauge at the helm, in idle or when throttling up, i have oil pressure and temperature gauges working.
Again, as per Bt Doctur, check the main engine harness to hull harness connection.
Next, check the actual tachometer connections under the helm.
If no go..... the tachometer itself may be bad.
Click to expand...
 
03, 25' crownline, 350 mag, Bravo III, 2 questions, this is my spring check up. drive is currently off getting painted and cleaned up. Boat is in my drive way. engine fired up and running first turn of the key not bad for winter break.
Question: with the drive removed, how did you supply cooling water to the engine located BIII seawater pump?
If this seawater pump was operated without cooling water, it may have become damaged!

In as little as 10 seconds too
 
on my boat raw water from transome has a tee vave, emergency shutoff as well and engine flush. Either the previous owner or crownline put it in. i can shut off raw water and take hose/drinking water to flush the engine while still in the water. i can also run the engine without the drive. more than 2 words.

off to go buy another sea water pump today, Hardin Marine pump as failed again back to back years.
 
so not so familar with the main wiring harness, i have been all over the bilge, i see the main CB on the block, it the harness there. please point me to the harness.

thanks
 
so not so familar with the main wiring harness, i have been all over the bilge,
Click to expand...

Ayuh,... There's a big ole black cannon plug where the hull side of the harness plugs into the motor harness, usually aft starboard side,....
The hull's harness then usually runs forward along the starboard gunnel,...
 
found the cannon plug, looks like a water hose because of clamp to keep it on. reseat and check still no RPM. i have the gauge out of boat. Is there a way to test the gauge with a volt meter?

Gauge is a Faria, 3 stud and 1 blade model #cs0466. does the RPM gauge/connection have an in-line fuse in the wire connections?
 
If you put power and ground to the appropriate terminals and then very quickly short the tach terminal to the ground terminal the gauge should go from zero to all the way max. SO BE CAREFUL NOT TO HOLD THAT CONNECTION. Simply tap it to see if the gauge responds.

other than that the only way to test is to hook it up on another engine.

Tach wire goes to the neg side of the coil.

YOU have not answered some questions.

1. is this EFI or not?
2. did you try the 4, 6, 8 switch on back of tachometer?
 
3-legged-dog said:
found the cannon plug, looks like a water hose because of clamp to keep it on. reseat and check still no RPM. i have the gauge out of boat. Is there a way to test the gauge with a volt meter?

Gauge is a Faria, 3 stud and 1 blade model #cs0466. does the RPM gauge/connection have an in-line fuse in the wire connections?
Click to expand...

If a fuse is present it would be for the power. Most likely not.

the power should come from the IGNITION on wire, Purple wire which should be daisy chained to several gauges so they only power on when the key is in the run position.
 
2003 MCM 350 Mag MPI, engine #0m366996, yes EFI i think, Yes on the switch on back of gauge, it was set to 3=8 cyc. i reset and retried same result.

ground wires all daisy chain must be 7 or 8 yellow wires on ground terminal, Battery terminal 2 purple wires, SIG 1 gray wire that travels into the console. and then the blade for light bulb. pretty staight forward.
 
so to confirm the test:
12 volt battery, positive lead to Batt on gauge
12 volt battery, negative lead to GND on gauge
12 volt battery negative lead to SIG terminal on gauge with a quick Tap, should bring a response to the gauge.
if it DOES gauge is Good, if no movement on the needle, then gauge is bad.
Am I Correct in the process?
Big Thanks
 
All this test does is tell you the gauge is functional not that it will read correctly

Because this is MPI you need a schematic to trace the wiring back to the origin.

I will look and see what I can see in the manual.
 
Last edited:
I have little experience with the EFI/MPI electrical so It will take a while to digest the schematics but,

because you did not state what you had in the FIRST post we all were talking like it was a standard NON efi/MPI system...............

YOU GUYS HAVE TO LEARN TO TELL EVERYTHING UP FRONT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

We waste too much time answering with the wrong information because we don't have all the right information.

You have several connectors and pins. many more than non efi/mpi system.
 
I believe this is the correct schematic. Could be wrong but if you can understand it maybe it will help.
 
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