Mercruiser IO water pump

[Skinned Knuckles]

I hooked up water to my girlfriends 1986 Mercruiser 260 Alpha One and started it up to get it ready for the summer and the manifolds got hot. I opened the drain petcocks and no water.I don't know anything about Mercruiser outdrives. Where is the pump with the rubber impeller located? Is there anything else that could be the problem? I have replaced such a pump on an old OMC I once had, is it a difficult job on the Mercruiser?

[Don S]

First thing you need to do is read a service manual. Here's an online version of the Merc manual for the drive. Service ManualHere is some other information you might find handy. Mercstuff

[rodbolt]

one thing ya may watch out for is occasionally a replacement motor has a belt driven seawater pump. it may or may not draw through the leg. inspect the motor for a seawater pump hanging down low on the stbd side. bit a buddy of mine

[BigPoppaG]

Don S. great online Service manual. I was looking at the breakout of the lower unit and noticed all the sealer/lubricants/adhesives and also the torque specs for it. Is all that necessary. I read several posts here that say how easy it is to change the impeller and none are this detailed. A little clarification would help.Thanks.

[Don S]

The torque specs and sealers pages show the information for all the lower unit, not just the impeller.But to answer your question, Yes, all of it is nessessary, but only if you want to do the job correctly.

[BigPoppaG]

Makes sense.

[rodbolt]

big poppa what I was getting at is contained in this short story. a buddy of mine, a welder by trade, bought a 26 grady in Norfolk. brought it home all happy and proud, hooked the muffs to the lower unit,fired that hummer up and overheated it. he called the original owner and found out that the replacement motor used a belt driven pump and used a thru-hull pick up. so my old buddy replaces the now destroyed belt driven pump, buys a flush attachement for it and fires it off again. man all is great. super duper he is gonna go fish in the morning. he finnaly called me about 7 am and said man I got a puddle of gear lube under the drive. I went to Chesapeake to look at the rig. seems the pump in the leg had run dry on his second attempt at running it on a flusher and melted the housing and the base. so that is why I said look closely at what it is. the place in the norfolk industrial park sold a ton of MIE motors for stern drive use. as long as corrosion around the lower unit studs is not bad the Alpha1 is not hard to do the pump on. get a manual and post us back with any questions and above all have fun. if it ever warms up. man todays weather was terrible. 4 trees down and I had to cut my way home with a chainsaw.

[Skinned Knuckles]

Thanks for the feedback, guys. I got the pump changed out today and that was the problem. The mercstuff link was a big help. I disregarded the instruction to drain the oil and remove the prop, figured it was proceedural BS.

[Don S]

Next post by Skinned Knuckles will be titled:Prop Froze on shaft...WHY?

[Skinned Knuckles]

Why would replacing the raw water pump cause the prop to freeze on shaft?

[rabidfish]

It won't. But, never removing the prop, never cleaning it all up and never regreasing will cause it. Don's point is this: This is no place to be lazy. Do it. Do it all or you'll be sorry. Not tommorow, but someday. This would be a great place for the link to the guy that had to cut off his Volvo prop. Alas... I dont have it... Don or Rodbolt might.Keep in mind that several of us make a nice living off guys who either didn't think it needed, or didn't know how to, properly maintain their boats. There is very little procedural "BS" as you put it. You'd be hard pressed to find a procedure that wasn't backed up with a pretty good reason for doing it.What Don did forget to mention... Welcome to I-boats... Glad to have you aboard!

[Skinned Knuckles]

We're selling the boat anyway, so there's not much reason to worry about the prop freezing. It's on a freshwater lake anyway.I don't have as much faith in service manuals as most people do. I met a fellow once who wrote service manuals for a living. He was not a mechanic. When I asked him he said "You don't have to be a mechanic to write shop proceedures, you just have to be a good writer".The purpose of proceedures is to make sure the objectives are met. Unfortunately, many forget that and the proceedures themselves become the objective.Another thing about manuals, they are produced by the manufacturer. When a certain part is prone to failure because of poor engineering, they will let you waste lots of time checking all kinds of other stuff instead of telling you where the problem usually is so they won't have to admit their own shortcomings.

[BigPoppaG]

Originally posted by rodbolt: big poppa what I was getting at is contained in this short story. a buddy of mine, a welder by trade, bought a 26 grady in Norfolk. brought it home all happy and proud, hooked the muffs to the lower unit,fired that hummer up and overheated it. he called the original owner and found out that the replacement motor used a belt driven pump and used a thru-hull pick up. so my old buddy replaces the now destroyed belt driven pump, buys a flush attachement for it and fires it off again. man all is great. super duper he is gonna go fish in the morning. he finnaly called me about 7 am and said man I got a puddle of gear lube under the drive. I went to Chesapeake to look at the rig. seems the pump in the leg had run dry on his second attempt at running it on a flusher and melted the housing and the base. so that is why I said look closely at what it is. the place in the norfolk industrial park sold a ton of MIE motors for stern drive use. as long as corrosion around the lower unit studs is not bad the Alpha1 is not hard to do the pump on. get a manual and post us back with any questions and above all have fun. if it ever warms up. man todays weather was terrible. 4 trees down and I had to cut my way home with a chainsaw.

Thanks rodbolt. I got some friends who do engine work on motors for boats and said they would help when I was ready. Like you said gotta wait for the weather. Snow expected today. It's CRAZY WEATHER!

[rodbolt]

hello the draining the oil helps prevent a heckuva mess. when the units are sepereated the upper will drain all over. removing the prop saves some weight that I dont have to lift and can assist in finger pinching. it also gives me a chance to inspect any anode and the seals for fishing line. as well as greaseing the prop shaft.

[mlslocks]

"We're selling the boat anyway"Is that like saying screw the next guy?

[rodbolt]

mlslocks its a buyer beware. if your looking to buy a used boat and they say it was just seviced or needs a tune up or an adjustment run very fast. the only way I would consider a just serviced rig is if they had all the service records and the records matched the service intravels. to many times the service was a patchem up and its gonna fail so they unload the rig and its the next guy's problem. happens everyday in this business. thats why I only fix them like the manual states. if they cant afford it or dont wish to they can pay for any time and leave.

[Skinned Knuckles]

Originally posted by mlslocks: "We're selling the boat anyway"Is that like saying screw the next guy?

Failing to remove the prop when doing a raw water pump hardly involves screwing anyone. I'm not even nibbling on your guilt trip, thank you. It's not like I'm covering up defects.

[Bond-o]

Failing to remove the prop when doing a raw water pump hardly involves screwing anyone. I'm not even nibbling on your guilt trip, thank you. It's not like I'm covering up defects.

Ayuh,........ You're Right.........Just Plain Lazy............

I don't have as much faith in service manuals as most people do. I met a fellow once who wrote service manuals for a living. He was not a mechanic. When I asked him he said "You don't have to be a mechanic to write shop proceedures, you just have to be a good writer".The purpose of proceedures is to make sure the objectives are met. Unfortunately, many forget that and the proceedures themselves become the objective.Another thing about manuals, they are produced by the manufacturer. When a certain part is prone to failure because of poor engineering, they will let you waste lots of time checking all kinds of other stuff instead of telling you where the problem usually is so they won't have to admit their own shortcomings.

Not Very Bright Either........

Why is there never enough time to do it right the first time, but always enough time to do it again?

You Might want to Read This,.. Before you pick up a wrench the next time..........

[Skinned Knuckles]

Bondo,If you fixed someone else's boat for free and failed to do any and all preventative maintainance on it that might be needed in the next few years, and some clown called you a such and such and a so and so for not doing it, what would you think of him?Get a life.

[trog100]

never spend too much time or money fixing your girlfriends boat.. she might not be your girlfriend for that much longer.. he hetrog100