Mercruiser 454 Starboard sea water pump orientation / direction

Beech2000

Active Member
Jul 11, 2015
242
NW Georgia USA
Boat Info
1990 Sundancer 350
Engines
2020 454 gen VI
Hurth V-Drive's
7.1 KW Kohler 5ECD
Amazing. I tried hard to ensure the raw water sea pumps get reinstalled in the correct orientation. Bad by me and did both Star and Port and now confused which hose goes where????
I marked the original water hoses on the housing. Problem is the housings are in the trash and on the way to the land fill. So, Considering the picture hopefully shown in this thread, which port is raw water "in" for starboard installation?
starboard%20raw%20water%20pump%20orientation.JPG
 
The answer is in your picture. What you really need to know is whether your engine is right hand or left hand rotation. At 1990, that could be a toss up. Most modern marine engines are all Left Hand rotation and the transmission does the reversing of the rotation.
hit the starter on each, and see which way the crank pulley turns when facing the front of the engine. If it turns to the right, you have a LH rotation engine (because you are in front of it) If they both turn the same way, you've most likely got 2 LH engines. Looking closely at the ports on the Raw Water pump, one is marked LH out, and the other is marked RH out. Both of my engines are LH rotation, so mine follow the arrow under the top (bottom) bolt. RH out is my inlet from the sea strainer, and LH out is my outlet to the Oil cooler. If your engines turn opposite directions, then the Starboard engine should be RH rotation. I only see that on direct drive boats these days.
https://bpi.ebasicpower.com/faq/rotate.htm
 
The answer is in your picture. What you really need to know is whether your engine is right hand or left hand rotation. At 1990, that could be a toss up. Most modern marine engines are all Left Hand rotation and the transmission does the reversing of the rotation.
hit the starter on each, and see which way the crank pulley turns when facing the front of the engine. If it turns to the right, you have a LH rotation engine (because you are in front of it) If they both turn the same way, you've most likely got 2 LH engines. Looking closely at the ports on the Raw Water pump, one is marked LH out, and the other is marked RH out. Both of my engines are LH rotation, so mine follow the arrow under the top (bottom) bolt. RH out is my inlet from the sea strainer, and LH out is my outlet to the Oil cooler. If your engines turn opposite directions, then the Starboard engine should be RH rotation. I only see that on direct drive boats these days.
https://bpi.ebasicpower.com/faq/rotate.htm

Thank you. Great information and it appears as if your response is spot on. Thank you for that!
I'm done with the Strbd engine. Trial start up didn't go well.....Yeap... Hoses were backwards. Not a big deal as I didn't leave it running for more than 2 seconds and figured out easier way to swap them.
Noteworthy: Looking from flywheel (rear) Starbd engine runs CCW. Best I can tell both engines run L/H. I used sharpie marker pens to mark the hoses for next time. At least I did on stbd engine. Tomorrow is port side day.
 
Counter rotating shafts will always (in my experience) spin the props outboard, but that doesn't tell the tale of how the engine is turning. I think otherwise, you would never get out of the water to get on plane. I think of the props as giving lift to the stern as they spin water up and out.
I did the long answer thing for someone searching the thread years from now.
Bump each one while watching the pulleys. That will tell the truth.
 
Reverse rotation now usually happens in the transmission not the motor.
If they are GM motors you can confirm the motors by looking at the firing orders. Locate number 1 by following the plug wire back to the cap. Now going clockwise follow the next wire to the plug.
8 is a standard rotation and 2 is a reverse rotation
 

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