Motorcycle Repair: 1965 150cc MZ motorcycle, size threads, motorcycle shops

Question
Need to find spark plug for 1965 150cc 2 cycle MZ motorcycle.  If anyone knows what size and where they can be purchased, it would be greatly appreciated.

Answer
Hello Carl,

That's a rare one to find parts for.

Original parts are of German origin
so the plug it used would be this:
Zündkerze AKA electric M 14-240

They are for sale on ebay in Germany I believe:
http://cgi.ebay.ca/Zundkerze-AKA-electric-M-14-240-/290484581564?pt=Autoteile_Zu...

My suggestion would be to try a motorcycle NGK B8HS spark plug.
Available at most motorcycle shops.

Make sure it is not the B8ES as it has a long
reach which might hit the piston.

The heat range should be about right.
If your plug burns black most of the time
you could go to a B7HS which is a hotter plug.

The NGK brand plugs are likely better plugs
than the old originals. Try them both and
see which you prefer. I find the NGK to foul
less than other brands.

If your spark plug hole has been modified you
will have to measure the hole and
find a plug with the right size threads.
They are usually 14 millimeters.

Spark plug color can be read,
a black plug is either getting too much
oil or fuel or is running too cold.

A very light colored plug is lacking
enough fuel or is running too hot.

When the plug is a light brown color
everything is running about right
inside the engine.

Good luck!
Wayne S.
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