BigBendFishing.Net

I am a DYI and was going to install a new pump in my 1996 150 Yamaha.

I have a factory service manual and it doesn't appear to be a big deal.

The marine shop charges $120 labor for this.

How many of you done this and am I asking for trouble? LOL

Dean

It's not a big deal to drop the lower unit. But you're talking about a 14 year old motor. If it's been in saltwater all it's life, be careful loosening each and every nut and bolt. Especially the water pump housing bolts. If you break one off you're in for a real treat. If everything comes apart OK, it's a walk in the park. The only problem you might have is aligning the drive shaft into the crankshaft. It's handy to have someone to move the flywheel to ease the process.

By the way, $120 Is about 1.5 hours labor. Let us know how long it takes.

tin can wrote:It's not a big deal to drop the lower unit. But you're talking about a 14 year old motor. If it's been in saltwater all it's life, be careful loosening each and every nut and bolt. Especially the water pump housing bolts. If you break one off you're in for a real treat. If everything comes apart OK, it's a walk in the park. The only problem you might have is aligning the drive shaft into the crankshaft. It's handy to have someone to move the flywheel to ease the process.

By the way, $120 Is about 1.5 hours labor. Let us know how long it takes.

I figured it would take me twice as long as an experienced mechanic, so three hours would not be that bad. LOL
That $120 would buy something else for the boat I need.

The boat has been in fresh water for the last 7 to 8 years and the pump was suppose to be changed two years ago.
It has a good stream of water, but wanted to change before the next season.

I hear you on breaking off a bolt.

On breaking the bolts loose - normally you are dealing with a stainless bolts and aluminum threads, so the threads are going to loose that battle every time. Using a sizeable rachet handle or wrench, hold it in place with your left hand and hit it firmly with the palm of your right hand (or vice versa if your left handed) when you break the bolt loose. As a kid, I worked on a lot of old Mercs and tried to ease them out slow - only to bring the threads out with the bolt. A mechanic friend showed me the method described above and it works most of the time.

Also, if you are trying to re-align the splines when you put the foot back on, you are better off to shift the motor into forward gear before you drop the foot. That way, you can shove up on the foot, move the prop a little to change the spline alignment, then try it again. I am not sure about the Yamahas, but the Mercs used to have a bolt hidden up under the trim tab on the foot of the motor. Check for that one before you start trying to force the foot off of the motor.

Good Luck - Steve Stinson

Thanks Steve, I was wandering why you couldn't put her in gear and turn the prop as you described, should work easier than turning the top of the engine.

Also, I think the diagram shows the bold under trim tab,

Good hint on the breaking loose the bolts, I would have tried the slow and easy method.

I knew you guys could give me some hints.

YOU MIGHT TRY SPRAYING THE BOLTS THE NIGHT BEFORE WITH CHEMTOOL, IF THE BOLTS ARE REALLY TIGHT HIT THE HEAD OF THE BOLT WITH A HAMMER WITH A FAIRLY HARD BLOW, THEN TRY REMOVING THE BOLT.
PA THE OLD MAN

Steve said forward gear. Butch and I always put it in reverse gear.
Like Pa said. Spray today,loose tomorrow.

There should be a plastic plug on the top of the midsection. Take the plug out with a screw driver and you'll be able to see the bole that goes into the trim tab.

Thanks chugbug

I knew there was a post long ago from a forum member DSTOCKWELL. I finally located it and here it is in case it helps. http://www.bigbendfishing.net/phpBB3/vi ... t=impeller

I did the water pump kit yesterday afternoon.

I put the engine in reverse before I started, this really helped in realigning the spindles of the shaft when I reinstalled.

No big issues and the hints sure did help. It probaby took me a little over an hour,

The bolts came out find, except I had one head that was sorta rounded out a little. Of course it was located where I could not get socket on it.

Also, the shaft collier, on top of the impeller, it took me a while to figure out how to get this off, ( had to pry up and off the metal shelve allowing the plastic to release/expand were it would slide up the shaft.

The biggest hint I can add to the list:
For sure put the impeller inside the housing before you slide down the shaft, getting it inside the housing is easier said than done, I finally took a med size plastic wire tie and complessed/tightened until it could wiggle it into the housing. I then cut the tie releasing the prongs.



I will for sure do it the next time, one of the easiest $120 I have ever made.

I also unclogged the speedometer water intake hole while I had the foot off. Now made be it will work.

Good Job!