70hp 1992 Johnson stripped spark plug hole

[DishMonkeySteve]

Hi all I was just changing my plugs and I noticed only the top one of the 3 was black...I had noticed unburned fuel in the lake so I wanted to change the plugs.
The top one wouldn't thread in easily, so I looked closer and the (cylinder head?) threads were all torn up. I did my best to get the plug back in cause we have at least 2 more months of boating.

Looks like I need to replace the cylinder head part 0435981 but clearly I shouldn't even change my own spark plugs. Any advice would be appreciated thanks.

 

[flyingscott]

No need to replace your head but it has to be fixed SOON. A heli coil or insert will repair the threads nicely.. If it is not fixed there is a good chance that the plug wil come out and cause more.damage.
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[oldboat1]

^^Agree. Not sure which model you have, but you have some repair choices: http://ww2.iboats.com/Cylinder-Crank...iew_id.1540448 .

You can purchase a new head cover, of course, along with a new gasket. You can look for a used head cover, or you can install a helicoil to repair the damaged threads. In any case, the head cover has to come off — not difficult, although salt corrosion can provide problems in a salt water motor.

A machine shop may be able to repair the damage for you or perhaps install a helicoil. Before reinstalling, you will want to resurface the mating surface of the head cover to get out any warpage, or have a shop do it. (Doing it yourself is very easy with a piece of wet/dry sandpaper and a perfectly flat surface.)

 

[boobie]

You don't have to remove the head to install the helicoil. I've done it many times. All it takes is some grease on the drill, tap and ect.

 

[DishMonkeySteve]

Thanks for the advice everyone. I'm relieved that I have another option.
We're in fresh water, glad I don't have to worry about salt.