reamed out spark plug hole

In my haste ( and in a fit of pissed-offedness) I reamed out one of my spark plug holes while I was putting in a spark plug. What kind of trouble am I in and what can I do to remedy this ?

 

Get ready to pull the head!

There is a kit you can buy at any good auto-parts store that will repair stripped plug threads with a steel insert, however, you will need to tap the old hole first. Tapping the hole leaves all kinds of metal shavings behind in the cylinder which is why you need to pull the head. I suggest you do all four while you have the head off.

 

KD Tool has a great thread repair kit for just this very occasion. You may not need to pull the head, though.

I've done the following and it worked well. Before you run the tap down the hole, take the left-hand side cover off and spin the engine counterclockwise until the piston is almost at top dead center. You want to leave it down far enough so the tap doesn't gouge the piston when you screw it in (that would be bad). Apply a bit a grease to the tap as you make your new threads. This will capture most of the filings. When you're all done, insert a small tube into the end of your vacuum cleaner hose and duct tape it in there. The tube should be small enough to fit down the spark plug hole. A drinking straw works well. Turn on the vacuum and remove any remaining debris from the combustion chamber. The reason you run the piston up to near the top is it helps any shavings from bouncing all over the cylinder by reducing their fall-velocity.

Hope this helps.

 

I agree. Pull the head and buy a heal-a-coil kit.

Or keep yer eyes open for a good used head on ebay. The used head is gunna cost a few more $ but might be the better option in the long run.

Or pull the head, take it to a machine shop and have them weld and re-tap the plug hole. Just a bit of a pain in the ass, but not that big of a deal.

 

It is not absolutely necessary to pull the head.
The Repair Kit comes with a two-stage tap.

If you follow the instructions on the packaging to the letter you'll get the steel sleeve in there without too much trouble.

Apply wheel bearing grease to the tap and the aluminum fragments will collect in the grease between the cutting edges.

What is paramount is the correct angle of the tap when you begin the work.
If you are tilted beyond the angle of the original hole it will cut new threads at that angle and the sleeve will be installed slightly cock-eyed making it an adventure to get a sperk plug socket on the Plug.

The Cylinder can be Vacuumed-out through the Spark Plug Hole.
Moving the Crank to open the exhaust valve will help with getting air flow into the Combustion Chamber for a vacuum break.

Use the Sleeve that is the correct length for the Spark Plug Threads.
Clean the tapped area free from grease.
Carb Cleaner will do the trick.

Apply a High-Temp Thread Locker to the cut threads and the Sleeves Threads and insert it by using a Spark Plug treated with NeverSeize.
Torque the Insert to specs.
Leave the Insert alone until the Thread Locker cures.

The only caution is written on the Package.
It's a "One-Shot Deal"
Take your time and get it right the first time and you'll be OK.

Good Luck.
Take your time.
Please keep us Posted!