70HP Evinrude 1981 Hydrolocking

kemosabe

Recruit
Joined
Aug 4, 2003
Messages
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I own a 39' Kayot houseboat moored in a slip at Wahweap Marina at Lake Powell. The boat is powered by twin 70HP Evinrudes that were original equipment on the boat when it was purchased new in 1981. The port engine is all original, the starboard engine had a rebuilt powerhead about 5 of 6 years ago.<br />We have an occasional problem with hydrolocking. The wind tends to come offshore and astern of our boat, and I think that wave action may be part of the cause. <br />Our current remedy is to remove the spark plugs, hold an oil absorbent pad over the engine, and crank it briefly to remove the water. We then spray some WD40 into each cylinder, replace the plugs, and crank her up. Unfortunately, this can result in quite a bit of oil and gas getting into the water. I am also concerned about a potential fire.<br />I am looking for ways to prevent this from occurring, and if possible a cleaner and safer way to solve the problem when it occurs. Thanks.
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: 70HP Evinrude 1981 Hydrolocking

Me thinks you have a leaky exhaust cover gasket or leaky head gasket unless the water is getting in through the intake silencer.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: 70HP Evinrude 1981 Hydrolocking

I'm sure that you have thought of flipping the boat around so the bow faces the wind & waves?<br /><br />You should be able to check for leaking exhaust cover and or head gasket by running the motor with the cover off. In any case you need to get it solved ASAP as water in bearings, journals and cylinder walls lead to rust even though you are in fresh water. Have you done a compression check?
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 70HP Evinrude 1981 Hydrolocking

From just sitting, there no way water could be traveling up the exhaust leg to hydro-lock the powerhead. Are you sure it's water that's locking up the motor? I've had cases where the float valves in the carb are worn and on a hot day the expansion of gas in the tank will force fuel past the float valves and puddle in the motor. Perhaps on a rough day it's enough to allow the fuel to puddle deeper in the motor, getting into whichever piston stopped at open ports...<br />- Scott
 
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