low--no--water pressure

[Redding XB21]

I have been dealing with over temp and low water pressure for two weeks. I took it in to a "premier" dealer here and he cleared the "faults" from the system(2006 250XS) and said not to raise it so much. I did not have this problem originaly and explained this to him. The Merc rep thought that the skid plate had something to do with it.
Bottom line, new water pump,cleared any debris from the pottet(?) valve and after idling for 1/2 mile , to leave the marina, got on it and the alarm went off right after getting on plane.

Any ideas! The water coming out the tell tale is cool to the touch but again 0 lbs. for water pressure. The computer listed the WP as 1.2 lbs when it alarmed and went into the protect mode.

Gene

 

[Redding XB21]

forgot----sportmaster lower unit

 

[FLYING BUTCHER]

water pressure

if you have checked all water flow passages then most likely you have something stuck in the water passage inside exhaust plate. I had a very small piece of wood stuck in on of the holes in the plate and caused same thing you are talking about, another possibility is exhaust plate gasket leaking. Hope it is something else as this requires removing powerhead. Good luck believe me I know how frustrating this can be

 

[jimmyb]

also, check the plastic pressure line that goes to the water pressure sensor (it is located on the top side of the coil plate on the back of the motor). The sensor will have a grey tube with a little push-lock style connector, you simply have to push on the fitting where the tube goes in and the tube will slide out. Disconnect the from the sensor, then disconnect from the engine block (another little fitting which is below the coil plate). Try to blow thru the tube... clean it out if it is clogged. My clog was where there is a "t" fitting... you should be able to figure it out

my tube got clogged with a bunch of mud because i idled out of a very muddy area this year... The next time out, i got very little water pressure...

also, the water coming out of the telltale is only water that goes thru a fuel rail and thru the compressor. It is a seperate cooling loop than the engine cooling.

honestly, you should be able to run a sportmaster jacked to the moon on the allison and still get LOTS of water pressure.

 

[Redding XB21]

Thanks for the input you guys Now lots of things to check. I hope I can get it cleared for this weekend--tourney time.

Gene

 

[badbait]

Gene, every 21 out of the Allison factory has that plate. I don't think that the plate has a thing to do with it. As far as jacking the motor up to high well since I know your fairly new with Allison's I'm sure Your running somewhere below the pad. I don't start haveing problems with water presure on mine until I get to 1 3/8 above the pad and I have the same motor and lower unit. I think you have something in there somewhere. Hope your able to solve the problem. Give me a call if you think I can be of some help.

badbait

 

[Redding XB21]

Thanks again guys. They found the problem wood in a screen into the power head. Yes, the powerhead had to be removed. OUCH. Naturally it was not a warranty item. I can't understand how debris can get all the way into the powerhead. Are there no filters prior to that screen? The mech said something about the design of the SM lower unit forcing water to the pump when running. There was no damage to the impeller when they changed that 1st and no chips to speak of at first checking. The thing that lead them to it was no/low block pressure.
Ran it on Friday afternoon and fished all day Sat. no problems. There sure is alot of debirs on Shasta and lots of big stuff when the lake fills.

Gene

 

[XB21er]

Glad you got it fixed Gene-

Craig

 

[jimmyb]

fortunately or unfortunately (depends on your perspective) there is not water filter or anything intended to filter the water going into the motor. The shape of the sportmaster case usually keeps weeds from getting sucked in... but it can happen, especially idling thru mud and junk

most filters would easily get clogged with weeds and other debris (it would suck to have to clean a screen out all the time, just ask the jetboat guys how fun that is) It is pretty amazing how much "stuff" a merc motor can eat besides water and still not clog the system... however once in a while, you get the weird shaped piece of wood or stone that gets thru the sportmaster hole openings and it gets clogged in the motor (usually in the thermostats or poppet)

 

[Redding XB21]

They checked the thermostats & poppet before having to pull the powerhead.

Thanks for the input Craig- see you in May!
Great pressure now. There is alot of "junk" in the lake right now and more to come.
I never had this problem in 20 years with my other LU on the XR2. There's got to be a way to prevent this.

 

[badbait]

Gene, glad you found out what it was. You can probably go another 20 years and not have that problem again. The wood this time of year is a problem and one of the reasons I've been a little hesitant to recomend Shasta for the Rally. Oroville Lake is the same situation.

 

[GFinch]

Plumb a sea strainer into the system. Saw this set up on a ski race Schiada mod vp tunnel boat.

 

[West Coast Bull]

Now that you got it fixed Gene.. How is the FISHING up there
mike

 

[Redding XB21]

toss it out & hang on :lol: :lol: :lol: :lol:

 

[WT]

also, check the plastic pressure line that goes to the water pressure sensor (it is located on the top side of the coil plate on the back of the motor). The sensor will have a grey tube with a little push-lock style connector, you simply have to push on the fitting where the tube goes in and the tube will slide out. Disconnect the from the sensor, then disconnect from the engine block (another little fitting which is below the coil plate). Try to blow thru the tube... clean it out if it is clogged. My clog was where there is a "t" fitting... you should be able to figure it out

my tube got clogged with a bunch of mud because i idled out of a very muddy area this year... The next time out, i got very little water pressure...

also, the water coming out of the telltale is only water that goes thru a fuel rail and thru the compressor. It is a seperate cooling loop than the engine cooling.

honestly, you should be able to run a sportmaster jacked to the moon on the allison and still get LOTS of water pressure.

8)

8) jIMMYB LOOKS LIKE YOU COULD HELP HE, JUST BOUGHT AN ALLY (1ST ONE) HAS A 1999 PROMAX 226 SPORT, LOW HOURS ABOUT 40 TOOK IT OUT FOR A SPIN I NOTICE TELLTAIL (PEEHOLE) DID NOT HAVE A STEADY STREAM COMING OUT OF IT. IT JUST KIND OF SPIT OUT, I RAN BOAT WATER TEMP ABOUT 150 DEGREES F WATER PRESS 5-15 PSI IS THIS OK OR SHOULD IT HAVE A STEADY STREAM FLOWING OUT OF THE PEEHOLE, IF YOU CAN TELL ME. GOD BLESS YA

 

[jimmyb]

WT

the water from your tell-tale on your promax is controlled by a thermostat and is usually a 140 degree. If the engine is cold or not up to operating temp, you wont get a steady stream out of the tell tale

 

[allison90]

ok

jimmyb, see if you can help me also! 99 225pro max. Water temp gauges on each head, right bank will get to 180 and set off alarm, left bank at 160-165. Changed water pump, switched thermostats. Water pump helped but after a long idle it will get up to 165, but wont set the alarm off now, water psi 8-15