73 4hp johnson seahorse water from sparkplug hole

[danray35e]

I recently purchased a 73 4hp johnson seahorse from a man. It looks great hardly a scratch on it. He said it was hard to start and had broken the rope trying. He said that was two years ago.

Well I took the carb off and cleaned it as I figure it needed it. I figured I would tear it down to replace water pump impeller just because of age. But I wanted to see if it would start. I put the foot in a tub of water just over the cav plate.

hooked it up to gas/oil mix and proceeded to crank it several times without so much as a hint of firing over. So I thought I would see if it was getting spark.

I took top spark plug out and cranked it once and it sparked great.
put it back in.

pulled bottom plug out and water dribbled out of the hole. So I am figuing a hole in the head somewhere. I got it off and saw it had a blown head gasket.

There doesnt appear to be any rust in the cylinder walls so I can only assume that water has not been sitting in there until I cranked it. With cover off I cranked it out of the water to dispel the water. Then sprayed wd 40 in and on the pistons.


But was concerns me now it if water made it into the crank case.

Should I tear the whole thing down now to make sure.

If so how do I go about getting the motor out of case to take it apart?

I have a manual coming but was not expecting this to happen and have no clue what I should do next, apart from getting a new head gasket.

I also took off what appeared to be and exhaust cover plate on the side.

I could see the sides of the pistons through four round holes and the route exhaust gas takes down to the foot. What bothered me was that I saw grooves on the pistons where I would have assumed rings would be. But I saw no rings.
Any help on this would be appreciated as I am lost without the manual.

 

[Rick.]

Re: 73 4hp johnson seahorse water from sparkplug hole

Never buy a motor with out checking the compression first. Like you need to hear that now. How do the cylinder walls look. For the rings to be gone I would expect the cylinder walls to be gouged and scratched. If they look O.K. then sand the head flat and put a new gasket in and re-install the head. With plugs removed, do a compression check and get back to us. I would not worry about the water at this point. Let us know your numbers. Best of luck. Rick.
Edit: put your exhaust cover back on too.

 

[danray35e]

Re: 73 4hp johnson seahorse water from sparkplug hole

Well false alarm about the rings. It was an optical illusion.
I gently slid the tip of my knife along the grooves and felt the rings. It just appeared as though there were no rings. As for the appearance of the cylinder walls they look normal for the cylinder walls i have seen. In fact they look pretty good. I went ahead and turned the motor on its side pistons down and rotated the flywheel to see if any water came from the crank case. I saw none.

I sprayed some more wd 40 . Considering I only paid 75 dollars for the thing I figured I could afford to fix anything that was wrong with it myself. If not while 75 isn't throw away money its not a huge loss for me at this time. But I can afford a new one.

 

[Rick.]

Re: 73 4hp johnson seahorse water from sparkplug hole

Ya I didn't want to call B.S. but I was thinking the rings were still there.
Don't underestimate that motor! I'm willing to bet your going to have it and be proud of it for a good long time. They are great motors. My good fishing buddy has the exact same motor as you and I reconditioned it four or five years ago and it still runs like a champ. I have a 71 that I use as a kicker. Do your compression check and we can take it from there. Rick.

 

[F_R]

Re: 73 4hp johnson seahorse water from sparkplug hole

You need to get that motor running ASAP. All that water in there is no different than if it had been dropped overboard. I hope you don't have to wait for a head gasket.

 

[danray35e]

Re: 73 4hp johnson seahorse water from sparkplug hole

I hope the same. I live in Panama city florida. Lots of boating around here so I imagine I can find one somewhere in town, I hope hope hope

 

[Rick.]

Re: 73 4hp johnson seahorse water from sparkplug hole

When you get the head gasket installed the torque is 60 -80 inch pounds. Start at the starboard center then port center up to port top and then across and down in a clockwise direction. Rick.

 

[danray35e]

Re: 73 4hp johnson seahorse water from sparkplug hole

Thanks Rick for all your help.