Cooling problems

[Chuck4741444]

This a total rebuild on 96 Johnson j150exedb.
I finally got the motor running 800 rpm and water pump building up good pressure, but with the hose Muffs. this was my second water do to my mistake.
Wednesday, I had finally got the boat ready to take to the lake to set the timing at wot.
Thursday morning, I put the muffs on to double check it before I drove an hour to the lake.
I didn't notice the muffs had slipped off and had no water.
fixed the muffs and restarted a after it had cooled down a few minutes. the pump was not pushing a hard full stream for the pee hole. ( I have noticed in between water pumps the starboard side ran hotter than the pot side, by touching the heads.)
so I thought it was the impeller gone bad, pulled the LU back off, the pump looked ok buy i changed it to be sure. it didn't pump no better than the old one (a week old) used a water hose to flush the motor from each thermostat hole, pee hole and up through the water pump tube.
I put the lower unit in a tub of water to test the pump, first i used a half in ratchet, it pumped a little, so I used a drill to pump it, while it was turning, I put my finger over the pipe and its barley sprayed, building up no pressure.
put it together, tested it and still no water at all. i put back together< ran the motor, not water. pulled the boat out of my shop and called it a day.
when changing the pump i notice it took a lot of pressure to push the housing down. but it was sitting in the pump housing properly. i pulled back of to double check.
could the gasket between the motor and mid-section gone bad from overheating? it did not get so hot that it killed the Motor, but it was too hot to touch. why does the new pump have very little pressure when I tested it?
I'm dealing with short turn memory problems that only get worse over time and this creates a lot of mistakes. but I'm committed to finishing this motor.
the only good news is that can pull and install the lower unit fast. lol
I have a Selco and Johnson service manuals. and double check the parts needed using Crowley marine parts list to insure nothing is being overlooked.

 

[saltchuckmatt]

Is your overheat alarm working? Have you done a compression check since this all happened? Approximately how long did it run with no water?

 

[Chris1956]

That waterpump should create 30+PSi at cruise speed. I have never had any issue with them but remove the water grates and see that the passage is clean.

A couple of notes. The gasket under the wearplate is glued to the gearcase. The oring under the SS cup uses some silicone to retain it, 4 drop is memory serves. Did you install the oring under the impeller? The impeller is locked to the driveshaft with the correct plastic key? You have a seal around the waterpump outlet? You used the correct (for your XL motor) water pump pipe extension?

Just some ideas....

 

[Chuck4741444]

Is your overheat alarm working? Have you done a compression check since this all happened? Approximately how long did it run with no water?

1. It ran 2 minutes max without water.
2. I dont think it has an over heat alarm. Its plug in the harness but i dont now where it would located.
3. Motor is rebuilded with less than an hour run time. Motor starts right up and idles good. i havent test compressi because motor run good.

 

[saltchuckmatt]

Alarm is either remote, incorporated in the control box, (most likely) or missing.

Do you have a omc/brp tach with check engine lights?

 

[Chuck4741444]

That waterpump should create 30+PSi at cruise speed. I have never had any issue with them but remove the water grates and see that the passage is clean.

A couple of notes. The gasket under the wearplate is glued to the gearcase. The oring under the SS cup uses some silicone to retain it, 4 drop is memory serves. Did you install the oring under the impeller? The impeller is locked to the driveshaft with the correct plastic key? You have a seal around the waterpump outlet? You used the correct (for your XL motor) water pump pipe extension?

Just some ideas....

Yes, book said to seal the top and bottom of the gaskt for the wear plater.

O ring gets 4 drops, one a each corner to avoid blocking the primer hole.

Oring under impeller and key in the slot.
Its the same extion i had before.
I can fell the water tube be pushing into the pump.

I have pulled the pump twice checking each step.
Im a retired sprinkler fitter, i know the pump is not pushing enogh water to reac the top of the motor.
Im going to check the inlet on the lower unit, its never been in the lake but it deffinitely needs to be ruled out.
I think the problem is in the pump but everthing is installed as the book shows.
The kit came with 3 orings but the book only show 2.
One under the impeller the other in the housing between the cup and housing.
I must be over lookung somthing.
I would pull it down today but im dissgusted with it, and fell like its a waste of time. I cant afford to take it to a shop or i would have by now.

 

[racerone]

???---2 minutes?----Might as well install a complete water pump kit.-----You ruined the pump housing and impeller !!

 

[Chuck4741444]

???---2 minutes?----Might as well install a complete water pump kit.-----You ruined the pump housing and impeller !!

The last one is brand new, i only ran it long enough to see if it was gong to pump water. It was not ran but about 15 to 20 seconds, so it didn'd burn up.

 

[racerone]

Water pumps are damaged in very short time.----Good luck with your motor.

 

[Chuck4741444]

Alarm is either remote, incorporated in the control box, (most likely) or missing.

Do you have a omc/brp tach with

I bought an after marked control box.
I could find the wire by color and add one.

 

[Chuck4741444]

Water pumps are damaged in very short time.----Good luck with your motor.

The last last one ran about 10 minutes, i said 20 but it was closer to 10 if that matters when runnig dry.
Ot did not show any signs of damage, did not has any rubbing scars, ss plate and cap look good. But i went a head and install the new.
Im fixing to pull it and if i missed somthing.
How long should it take water reach the pee hole? Average time.

 

[Chuck4741444]

The last last one ran about 10 minutes, i said 20 but it was closer to 10 if that matters when runnig dry.
Ot did not show any signs of damage, did not has any rubbing scars, ss plate and cap look good. But i went a head and install the new.
Im fixing to pull it and if i missed somthing.
How long should it take water reach the pee hole? Average time.

I pulled the the lower unit put, removed everything.
I was missing the garment inside the wp hose housing.
I put it back on the muffs. Removed the thermostates and the plugs for them. Its peeing 1/4 the water it should be, the same as the last pump.
I have water coming up and pouring down around the heads and cooling the heads on the port side. To hand touch.
Starboard side is dry, only once did i see water spilling over to supply water to cool the head. It started heating so i Killed it.
Looking a cooling water flow chart.could it be damaged gasket between the block and midsection ? ( its new)
During my hoes test, water was flowing from side to side using the t stat holes.

Everthing was fine before itbwas rum without water. Thanks for the help.
Sorry if im wasting your time.

 

[cyclops222]

Did you ever have this motor running on a boat at good speeds ?
Or is this a unknown motor ?

 

[Chuck4741444]

Did you ever have this motor running on a boat at good speeds ?
Or is this a unknown motor ?

I rebuilt it this winter. It starts and runs?. It runs good. Was taking it to the the lake to set wot timming.
When the water was flowing good, i had concerns the port side ran cooler. But starboard side was warmer.
Its pumping water, but its not getting to the power head. It leaking somewhere to prevent it from making presure. Is there an orfice that slows the hot water so the coolong system can presurize?
And let the hot water drain out slowly?D

 

[Faztbullet]

Is there an orfice that slows the hot water so the coolong system can presurize?

Yes..they are the t-stat/poppet assembles. Do you have a factory manual?

 

[Chuck4741444]

Yes..they are the t-stat/poppet assembles. Do you have a factory manual?

I have the manual.
I beleive you have answered my question.
My test was without the t stats. I was thinking one was bad so i removed it. I will test them today and see it they open at the right temp before i install them.
Thanks For your reply.

 

[saltchuckmatt]

If using in salt water, I replace every year or drop them in salt away until spring.

 

[Chuck4741444]

Up date. I tested the t states at 145 +- they are good.
Idle 1000 rpm post is running 120 to 130
Starboat side 150 +-

At 800 rmp they both rise but starboard side close to 170. Then i shut it down.
This on the hose. I dont think the tell tale is not puting out as much water as it had last week.
Manual says to run it at @ 3000 rpm in a body of water for min 5 minutes. Then test the temp. Should be at 155 degree.
Because my numbers are too high at 800 rpm, im going to replace the wp one last time before i just park it.

 

[saltchuckmatt]

Might run a hair over... overheat in certain conditions until you take it out make the poppets open but if you have no flow you have no flow.

Could be a bad gasket?

Did you replace the entire pump assembly or just the impeller?

 

[cyclops222]

How about a BAD ? INCORRECT head gasket ? Or installed wrong way. If possible. On the bad side ? Rare but it fits your problem.