[RBBH]

I recently bought a boat from a friend of mine. It has a 40hp mariner magnum(1994). Water just trickles out at idle and will run a little harder when reved. My alrm goes off after it gets warm and a little steam came out with the water.

Do I need a new pump?
How much is this going to cost?
Is this something I can do on my own, I am very mechanical?



Thanks

 

[Stubby]

Welcome to the BOC------Yes you need a pump----Look under the Member Libary and the How to information for lots of help on this subject. And Yes it is something YOU can do at home. in the area of 25/30 bucks if you do it.

 

[larry again]

hi dustin, yes this something you can do, but it sounds like your thermastat is bad.I change both the impeller and thermastat every two years better to be safe than sorry! buy a book and parts under 125.00 dollars a new outboard is about 6,000.00 $$$$$$$$$$ good luck and good fishing:smile2::smile2::smile2:

 

[AwShucks]

Carl's right and Larry's right also. It is probably more in the line of a badly worn impeller. Parts run in the price range stated. You can usually get an impeller at your friendly auto parts store. They probably won't have it on hand, but can get it in one to two days. If you have one, follow the instructions in the manual, if not, see if you can visit your local library and xerox copies on the impeller change. Normally takes a half inch, 9/16 inch and 5/8in box wrench. You should get in a habit of checking, if not replacing the impeller on a regular basis. I'd have one on hand when checking so it could be replaced if needed. This is the type of surgery that could be done at the river also, as long as you could get to the lower unit. LOL. I know thermostats go bad, but I don't change them unless needed. Actually, (keep this at a whisper) I removed the one from my 50 and 70 HP motors. Installed a water pressure gauge though. When the audible alarm goes off, it is generally to late.

 

[Bubbakat]

keep this at a whisper) I removed the one from my 50 and 70 HP motors. Installed a water pressure gauge though. When the audible alarm goes off, it is generally to late.


Lawerance Put those stats back in those engines. They are there to bring those engines up to the proper working temps to help burn the fuel correctly.:wink:


As for the Tstat on that mariner I doubt its bad but If I didn't know when it was changed l;ast I would spend the few bucks and chang it if it has one. On the water pump My suggeswtion is to install the whole pump because you know nothing about this one you have. The wear plate and cup will get grooves in thewm and will cause an over heat also. Don't take that impeller out and report back that it looks good because with them looking good doesn't make them pump good.

 

[RBBH]

I just got back from the boat shop and I picked up a new impeller. I got some pretty good directions from the mechanic on duty. I'm going to give it a try this week.


Thanks for the responses

 

[BailBonds]

I'm sure the mechanic explained to you that you can put the impeller in backwards by twisting it the wrong direction. I replaced a thermostat that was good one time with a brand new defective one. Tell me that didn't drive me nuts. The old "it can't be the thermostat it's a new one". I finally put it in a pan of water and heated it up. Never opened. Sometimes if it ain't broke don't fix it is the right way to go. If you don't have a shop manual for this unit I'd get one.

 

[Bubbakat]

You need to turn the shaft in a clockwise dir to get the cup on and to make the tines go in the right direction but don't worry about the directions of the tines to much because when you start that engine those tines will right themselves but go to the library and look at the water pump tutorial we made and put in there to help you with this.

 

[RBBH]

I guess I'm a little confused about the tines/shaft you are talking about.

I tokk the lower end off and it came a part pretty easy. Then I took the three bolts that hold the impeller housing off. I then lifted up and the housing slid up the shaft and I was then able to slide off the impeller. It looked to be in good shape but we will see. The new part was the wrong one. I have to go back today and get the right impeller. The only mistake I made was not paying attention on the old impeller to the derection of the fingers. It looks like a pinwheel. I just figure that they are made to run the same direction as the engine, which is the clockwise you are talking about(I'm guessing).


Thanks for the help guys!

 

[RBBH]

I fig'd out the direction of the fingers. My impeller was bad enough that the rubber tips were pointed one direction. The new one is straight.


thanks

 

[peewee williams]

I checked all new thermostats on every kind of engine before installing and checked it every time I changed water pumps on every kind of engine.Make sure that they start opening at the right temperature and make sure that they fully open by the right temperature.Make sure they start closing and do close at the right temperature.New does not mean it is right!I have found several new ones to be bad.Opening and closing does not mean it is right.Opening and opening fully and closing at the right temperatures has to be right.Thermostats have a correct cycle,not just to open and close as we think.This is from old Diesel Mechanic,40 Horse and Under Outboard Motor and Small Engine repair schools I have attended along with the heart break of personal experience.And yes,some small engines have been water cooled.

I set a thermostat on a ceramic or glass surface inside a pot and put the thermostat on or in it.Metal to metal contact of the thermostat with the bottom or sides of the container will cause the thermostat to heat unevenly at times.Avoid this.Also your thermometer should not not touch metal.Heat it slow and watch closely.When fully open,watch when it starts to close and when it closes completely.You will often be surprised.

Also.A "wax filled",sometime listed as "heavy duty" thermostat generally last far longer than the gas filled in everything.They are more expensive,but have been well worth it in my opinion.You take what you can get with outboards.

Also gaskets.I buy two to have a spare.Small (40 & under)outboards I Never Seize (Nickle only,no Copper!)coat the gaskets and they are reusable until they harden.If they do leak or seep it is easy to see and correct.

Some use to offer two different temperature thermostats for the same motor.I trolled and idled a lot working with my 9.8 Mercury.I believe that the slightly hotter thermostat that Mercury recommended worked better year round for me.Also,my motors were run at 2/3 throttle on the top end and never reached the upper levels of the designed heat range.Also they had a cold weather package that circulated hot water around your carb that worked great in cold water after you got some water heated in your engine.If your water never gets below 40 degrees,I don't think this would be worthwhile.It was a help the few times our water temperature got real low in South East Georgia,but really shined in northern winter trips!

I have a 2 cylinder Mariner manual 40 that has been as good a motor as I have ever had.It pulled a 30 foot Scorpion (big for it's width balloon net with lots of webbing) Shrimp net for 4 years along with many hours of "chasing the birds" offshore,inshore oystering,clamming and fishing.

I hope this helps someone.

I love you Brothers and Sisters.peewee

 

[drpepper]

You need to turn the shaft in a clockwise dir to get the cup on and to make the tines go in the right direction but don't worry about the directions of the tines to much because when you start that engine those tines will right themselves but go to the library and look at the water pump tutorial we made and put in there to help you with this.

oooh: Ooooh crap... :crazy: my freakin' heart just about flopped outta my chest when I read about the tines being in the wrong direction!

I JUST "rebuilt" my pump and I'll be dang if I can remember which way I rotated the shaft to get the tine inside the housing.... thank God Bubba made that post or I'd be rippin' it all apart and redoin' it all tonight so I could sleep... before I start the motor (engine) lemme double check... it's OK if the tines are backwards right?:confused2:

 

[AwShucks]

Seems like Fuzzface and I rebuilt a water pump. Put the impeller in backwards, ran the motor, took the darn thing apart again, and the impeller was still backwards. So, now we both check the darn thing, just like a heart surgeon. LOL

Last impeller we replaced, the motor wouldn't pee no matter what. We must have removed that lower unit, disassembled the water pump five times. Just getting ready to use a ball peen hammer on the blankety blank blank. Put it back together to take to the shop, when I happened to think... do we have that lower unit deep enough in the horse trough. Tilted the front of the trailer up, added water, started it up, and there it was in all of its glory. You gotta have enough water in the tank. LOL

 

[peewee williams]

Seems like Fuzzface and I rebuilt a water pump. Put the impeller in backwards, ran the motor, took the darn thing apart again, and the impeller was still backwards. So, now we both check the darn thing, just like a heart surgeon. LOL

Last impeller we replaced, the motor wouldn't pee no matter what. We must have removed that lower unit, disassembled the water pump five times. Just getting ready to use a ball peen hammer on the blankety blank blank. Put it back together to take to the shop, when I happened to think... do we have that lower unit deep enough in the horse trough. Tilted the front of the trailer up, added water, started it up, and there it was in all of its glory. You gotta have enough water in the tank. LOL

Many of the 6-15 Mercury motors have the water pickup under the cavitation plate right above the prop instead of down on the gear case like most motors.It is easy to mount them too high in a barrel,tank or even on the boat.

I love you Brothers and Sisters.peewee