9.9 Johnson Replace head gasket or....

[Bullie]

I sold this 9.9 10R74S to a fellow a couple months ago. He used it a few times frog hunting and said it did fine then he thinks it stopped pumping water. But, he kept using it until it quit running. The head gasket is definitely blown. But, I don't know how to determine if it will need more than just the gasket replaced. I have taken some pics of the cylinders.
#2

#2

#1

#1


#1 tested to 91 PSI. #2 tested to 68 PSI.

The water pump was new and I tested the thermostat on the stove. It opened at 155 F.

What do I need to do next?

 

[flyingscott]

You should have done a compression test the thermostat should open at 143. Did you warranty the motor because frog hunting is usually done close to shore where its weedy. My rule of thumb is if my fingernail catches in the score more than .010.

 

[oldboat1]

Have a comp test as a benchmark before it went to the frog hunter? Don't think the t.stat was the issue, but might stick in another one (143 degree), with cover gasket and head cover gasket and see how she does. Resurface before installing gaskets, and clean out water passages. Might run out OK even with scoring.

 

[Bullie]

You should have done a compression test the thermostat should open at 143. Did you warranty the motor because frog hunting is usually done close to shore where its weedy. My rule of thumb is if my fingernail catches in the score more than .010.

I posted the compression numbers in the OP. They were 91/68. The buyer said it was really nasty water they were in. Maybe the inlets were covered. I have not seen any trash in the motor.

I do not remember what the compression numbers were originally but I am sure I was pleased with the them or I would not have sold the motor. Maybe they are in my notes on the motor...I will have to check. I am hoping that a new head gasket will get it running. I will try that.

 

[Chinewalker]

By the scuffing visible in the photos, I don't think a head gasket is going to fix the issue. I'd bet the new owner sucked weeds over the intake and cooked her, which in turn blew the head gasket, made worse by his admission that he continued to run it after it stopped pumping. You're off the hook on this one.

 

[oldboat1]

yeah, see it as the frog hunter's problem too. But if it's passable with a head gasket, and he can get back out into the bullrushes, he'll probably be fine and you get rid of the motor. Maybe he learned something. Probably not.

 

[NAT1VE]

Is that the camera or casting on the piston? Looks like a crack at about 9 o'clock.

Be sure to check the cylinder walls and the water-jackets surrounding the cylinder walls for any hair line cracks. I would use 400-600 wet sand paper on the walls. A few passes clockwise, then a few counter-clockwise to mimic the factory crosshatching. Then take a straight edge to the Head and check for warpage, as well straight edge the block. Because if the heads warped and you don't sand it flat(figure 8 pattern) to get it evenly flat. Then a new head gasket will leak again, and you'll be back at square one.

 

[jrs_diesel]

NAT1VE, that looks like casting. That line goes all the way across the piston top.

 

[boobie]

If it was my motor I'd make sure the head is flat, clean up the gaskets surfaces, put it back together and see what happens. JMO.

 

[Bullie]

I got new gaskets, wet sanded the head on glass, dropped in a new thermostat, and put everything back together. I got 110/108 compression and it started on the 3rd pull. It seems to be running fine but it is not pumping water out the blubber hole like I remember it doing. I ran the motor for a considerable time while monitoring its temp. I never read a temp over about 160 anywhere. But, only occasionally did the water really exit the blubber hole with much force. Most of the time it was a fine mist. I back flushed the motor from the blubber hole but didn't get a chance to see if it made a difference.

When water would exit the hole with force it was only intermittently. Maybe 3-5 seconds at a time and then would go back to a mist.

I didn't find any debris, other than a little flaking paint, anywhere in the water passages. I have no idea why the water isn't spewing from the hole when the thermostat opens.

 

[raczekp1]

install new water pump impeler.
if problem still exist it means upper grommet is lockhed like here:

 

[raczekp1]

install new water pump impeler.
if problem still exist it means upper grommet is lockhed like here:

 

[Bullie]

I can install a new impeller. The one in it is less than 4 months old. I probably need to make a video where you guys can see what I mean about the water spewing out normally for a few seconds at a time.

 

[Chinewalker]

The "blubber hole" as you call it is an exhaust relief. Only some of the exhaust water comes out of there as most of it goes out the prop. Sounds fairly normal to me. Your thermostat likely opens around 140 and gives operating temps around 160, so i think you're in the ballpark on that.

 

[Bullie]

I guess I picked up "blubber hole" from reading Leeroys Ramblings so many times. LOL

I still don't completely understand the water routing in these motors. I suppose I assumed that anytime the thermostat was open a considerable amount of water would exit from the exhaust relief. Could the thermostat only be opening for a few seconds at a time as it will spray for a few seconds then go back to a mist? Or am I still missing something?

 

[Bullie]

Another question. Is there a tool made to remove the LU seals? Or can someone explain an effective way to remove them?

 

[AlTn]

have you checked out Leroy's Ramblings..johnson/evinrude 9.9/15 hp maintenance and repair website?

 

[tomhath]

Another question. Is there a tool made to remove the LU seals? Or can someone explain an effective way to remove them?

There is a tool to remove seals, it has a hook one one end and a handle you hit with a hammer on the other.

I wouldn't expect much water out of the exhaust relief at low RPMS, especially if you're running it in a barrel and the water level is a bit low.

 

[ttankmoran]

If you're running it on muffs you wont see more than a slight mist from the blubber hole. If you are running it in a trash can or something where the water level is similar to where it is when its on a boat in the lake you should see considerably more water coming out.

If you are running in a trash can and only seeing a slight mist then you're either not pumping enough water, you have a fried water inlet grommet as shown in the picture a few posts above, or perhaps some other blocked water passages in the engine still.

 

[jrs_diesel]

Mine only blubbers some water out when I'm running at high speed across the water out the exhaust relief, otherwise it's only a mist. Tell tale stream is strong, no cooling issues with my motor. I've never had it blubber while on muffs or in the water barrel.