How to make a spark plug into a "Greaseplug"
There was a bit of discussion on the Yamaha XS650 list about how to break
a seized engine. One method stated was to pump a cylinder up with grease
from a grease
gun and the hydraulic pressure from the grease gun would bust the engine
Doing this through the spark plug hole seemed to be the best option. There
was talk of
drilling out a bolt with the same threads as the plug and installing a grease
zerk on the end,
or having a machine shop make one up specially. Finding a bolt
with the right sized threads might be
a problem for some and a machine shop might want more money than you want
to spend to make one up
for you. I conceived the idea that it could be done with a hollowed
out spark plug and a grease zerk.
So here's what I did:
(click any pic to enlarge)
Here's a used BP7ES plug from the plug bucket.
Here's the plug, mounted in a vise.
Here's the hammer I used to smack off the insulator
I would suggest wearing some sort of eye protection
Grind off the ground hook on the bottom of the plug
Use a punch and hammer to pound out the ceramic.
It won't pound through, just bust the ceramic into little pieces
and dump them out.
It may take some hammering, but eventually, you'll have a hollow plug.
I found some grease fittings at the local parts store.
The base is 1/2 inch in diameter.
Since the parts were such a close fit, there was no need to tap the spark
Just take a wrench and tighten it on in. You may wish to braze them
So there you have it. A bit chewed up from being in the vise, but I
think it will work
and it only took me 15 minutes to make. It took me longer than that
to post all these pictures!
Remember, if you plan to do this, make sure that both the valves on the cylinder
are CLOSED. Otherwise,
you will have an even bigger mess on your hands!
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