water pump, any thoughts before I pull the boat???

[reefman]

Ran the boat all day Sunday with no issues. Go down last night and within 50 yards from the slip the overheat alarm sounds. I realize that I'm not getting a drop from the telltale. Back at the slip I tried a little piece of wire inserted into the tube and also blew some air into it with no results. Water pump was replaced last spring and has worked perfectly. Tried running it with ears on and same thing, not a drop. That is it for my bag of tricks, any suggestions? If I dohave to yank the boat is it dangerous to run three minutes to my ramp with the alarm sounding? Thanks for any help you all can provide.

 

[TheOtherLine]

Not surprising that it doesn't pee with ear muffs. Is your motor a larger four stroke? If so, it probably won't pee on muffs.

Anyway, could also be a bad impeller. Similar symptoms and will cause an OH alarm.

 

[Brent]

Was the complete water pump replaced? I asked b/c SIM Yamaha has a 3 different water pump rebuild kits posted on their web page.
Maybe only a partial rebuild or just the impeller was replaced

 

[fogwarning]

Did you run through any sand or mud last time you put her in the slip? Any change you picked up a load of gunk from the bottom and you now have a clog in the cooling system?

 

[TheOtherLine]

Was the complete water pump replaced?

:!: I'll bet they just replaced the pump and didn't do the impeller...

 

[Megabyte]

Some shops only do the impeller if that is what you ask for.
When I get mine done, I ask to have the whole pump replaced.

 

[CaptainJim]

i've had similar issues... and my water pump was only a year old as well.

my suggestion is replace the waterpump and the t-stats... the full kit is about $90 and the tstats are like $25 each.

i did it myself with a buddies help in the parking lot. its easy as hell and i'm no mechanic

 

[johnsw]

If yours has one, don't forget about the pressure relief valve. On my '04 150 2 stroke, it's mounted close to where the tube comes from the motor for the pee strream. I had sand caught in mine once causing it to stick open. When that happens, the water pressure in the cooling system doesn't build up and I bearly had a dribble coming from the pee hole. I also overheated just a few minutes after leaving the dock. The water pump was done that spring before launch, so I looked elsewhere for the problem.

While I was working on it, I also added a temp guage that i can switch between independet temperature sensors on each cylinder head. Now I can tell if I run hot on one side or both, and what my normal temperature range is.

John

 

[DaleH]

I'll bet they just replaced the pump and didn't do the impeller ...

Huh ... and just HOW would one do that? :?: Which part do you think is the 'pump'? The cover, the wear plate, the rubber grommet on the cover, or the rubber grommets to the water tube ... ? Fact is, there ain't no 'pump' without the impeller! And to add, the impeller would need to be removed to replace half of those listed.

I'd bet $$ it's in the exit tube from the head or poppit valves, if indeed this motor had a recent FULL waterpump service.

IMHO, only on small OBs to 25hp or so it is possible and practical to just replace the impeller during a service. And as others said, t-stats should always be done when the water pump is serviced.

 

[Megabyte]

And as others said, t-stats and poppit valve(s) should always be done when the water pump is serviced.

Fixed it for ya.

 

[DaleH]

And as others said, t-stats and poppit valve(s) should always be done when the water pump is serviced.

Fixed it for ya.

Yeah ... but that applies to Yummiehas only! No other OB brands suffer the deleterious effects of crapped up poppit valves and clogged up VST filters et al :roll: like Yams do.

 

[TheOtherLine]

I'll bet they just replaced the pump and didn't do the impeller ...

Huh ... and just HOW would one do that? :?:
IMHO, only on small OBs to 25hp or so it is possible and practical to just replace the impeller during a service. And as others said, t-stats should always be done when the water pump is serviced.

I stand corrected. I was referring to this piece and this piece only.