Water on spark plugs, 1969 johnson 33HP

[JerryNicksDad]

I was out on the lake when the engine suddenly started to race in choppy water and then lots of air coming from the water intake area and all forward motion stopped.

I throttled back to idle thinking the motor water intake just sucked up a lot of air, then slowly started to throttle forward when I realized something very bad was happing because I was at half throttle but the boat was barely moving.

I then headed back to the ramp area at full throttle not going much faster then idle speed.

When I took it out of gear I was able to run the throttle up full and it sounds good.

I was able to get back at half throttle doing about five miles per hour.

Is this a bad head or could it just be a bad gasket, after investigating I did notice that I had a few lose head and exhaust cover screws.

(Just told the family we will not be spending the day on the lake today....OUCH)

Thanks in advance for any help.

 

[Molaker]

Re: Water on spark plugs, 1969 johnson 33HP

Sounds more like you may have sheered a prop sheer pin. The air in the water is most likely normal exhaust for the RPMs you are turning but didn't notice before because you were moving away from it faster. Pull ypur prop and check. If the sheer pin is bad you could be back on the water pretty quick. Do tighten those head cover screws - but not too tight. You don't want to twist them off. A little thread lock would help prevent them from working loose again.

 

[tashasdaddy]

Re: Water on spark plugs, 1969 johnson 33HP

if the engine is reving like a clutch slipping on a car yes the shear pin. or a spun prop.

 

[JerryNicksDad]

Re: Water on spark plugs, 1969 johnson 33HP

I checked the prop out first, the prop is fine. The motor under load bogged down while I was on the lake.

I was hopping it would be a pin, that would be the easiest and cheapest way out.

Thanks for your input guys, please keep up the good deeds..

 

[JerryNicksDad]

Re: Water on spark plugs, 1969 johnson 33HP

OK, I know this is not a good thing. LOTS of water on the bottom spark plug, but the top plug is clean and dry except for a little oil. after I ran it for a few min. "ran rough".

What is the next move?

 

[Molaker]

Re: Water on spark plugs, 1969 johnson 33HP

Is this a bad head or could it just be a bad gasket, after investigating I did notice that I had a few lose head and exhaust cover screws.

If you had loose head bolts (not just head cover bolts) and water on a plug then there is a good chance the head gasket is blown. Pull the head and check. When replacing, be sure to use a new head gasket and torque the head properly.

 

[JerryNicksDad]

Re: Water on spark plugs, 1969 johnson 33HP

That was it, the copper ring of the bottom head gasket was bent and torn apart from the rest of the gasket, that made holes.

Thanks, it was a piece of cake to remove and Napa auto will have a new one for me tomorrow.