1986 70 hp Yamaha 2 stroke outboard water pump

[woodgc]

Hi,

Looking for some directions/instructions on replacing the water pump on my 1986 70 HP Yamaha. Symptoms are the alarm comes on and the "pee' stream looks small and weak.

Could someone Please tell me what I need to do to replace the water pump and if there are any hidden pitfalls I need to watchout for. What's the best replacement pump?

My email is woodgc@gforcecable.com

Thanks in advance
Woodgc:'(

 

[avirex7823]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

That's a pretty easy job replacing the water pump. First, place the engine in neutral gear..You need to remove the prop for safety reasons. Also tilt the engine up as far as it will go.. Disconnect the speedometer hose, and remove the four or six bolts that holds the lower unit to the lower engine housing. It's best to have a helper to hold the lower unit while you are dropping the L/unit... When you have lowered the L/unit, you will have a long shaft with splines at the top.. You will also have the shift lever rod near the shaft rod. DO NOT turn or rotate this shift rod while working on the unit.
At the base of the shaft rod is a shinny metal housing with four bolts, inside this housing is the "impeller" water pump...

It's best to replace the Impeller with a OEM Yamaha water pump. You can order one and the necessary parts from Boats. Net.. The impeller is #6H3-44352-00 at $20.70. You will need to place the gaskets, and bottom plate and metal housing. All these parts should run about $50.00..
NOTE: DO NOT remove the impeller (water pump) till you have the new one, and make a diagram how the old one is placed in the housing... The new one "must" go back in the same position..

 

[woodgc]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

That's a pretty easy job replacing the water pump. First, place the engine in neutral gear..You need to remove the prop for safety reasons. Also tilt the engine up as far as it will go.. Disconnect the speedometer hose, and remove the four or six bolts that holds the lower unit to the lower engine housing. It's best to have a helper to hold the lower unit while you are dropping the L/unit... When you have lowered the L/unit, you will have a long shaft with splines at the top.. You will also have the shift lever rod near the shaft rod. DO NOT turn or rotate this shift rod while working on the unit.
At the base of the shaft rod is a shinny metal housing with four bolts, inside this housing is the "impeller" water pump...

It's best to replace the Impeller with a OEM Yamaha water pump. You can order one and the necessary parts from Boats. Net.. The impeller is #6H3-44352-00 at $20.70. You will need to place the gaskets, and bottom plate and metal housing. All these parts should run about $50.00..
NOTE: DO NOT remove the impeller (water pump) till you have the new one, and make a diagram how the old one is placed in the housing... The new one "must" go back in the same position..

 

[woodgc]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

THANK YOU avirex7823,

Thank YOU ever so much. Nice job on the instructions.

Doesn't sound too hard, as long as I don't move the shift lever and get the new impeller back in just like the old one.

Do you think I need to flush out the water paths incase any of the old impeller came loose and made its way into the cooling water paths and could cause a reduced flow with the new pump?


Have a nice evening
Woodgc8)

 

[boashna]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

http://www.thehulltruth.com/forums/thread-view.asp?tid=79469&start=1

http://2coolfishing.com/ttmbforum/showthread.php?t=50890

above are two good leads with pics .

 

[boashna]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

http://www.thehulltruth.com/forums/thread-view.asp?tid=79469&start=1

http://2coolfishing.com/ttmbforum/showthread.php?t=50890

above are two good leads with pics .

 

[woodgc]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

Thanks boashna,

GREAT info, with pictures. Super help to me.

Keep smiling
Woodgc8)

 

[Ray Neudecker]

Re: 1986 70 hp Yamaha 2 stroke outboard water pump

Putting the shifter in neutral before removing the gear case and being sure it and the gear case are both in neutral when reinstalling will make the job easier.