meirman wrote:
Is it possible to get an 18MM spark plug for a lawn mower?

And does anyone have a brand/number for one?


The original plug was 14MM (a Champion RJ19LM) but it seems the
previous owner drilled out the hole and it is now about 18MM. (I hope
it is exactly 18mm, but I won't be able to tell until I buy a plug.)

The recommended 14MM plug has what I think is a short reach. The
threaded part of the plug is 3/8" long, and if one includes the
electrodes, the distance from underneath** the washer, past the
threaded part, to the end of the ground electrode is 1/2".

**Maybe the "reach" is measured from above the washer. If so, both
lengths should be 1/16 inch less.

I bought this Craftsman lawnmower second hand, and when I got home,
the mower looked even nicer than I thought, but had no spark plug. I
took plugs out of my two old mowers (which don't work or don't work
well) and the hole was too big for them. I went to Sears and all the
plugs they had for sale had the same size threads as the ones I had
tried, 1/2 inch in diameter, which I guess is 14MM.

I think the hole is 18MM now.

Thanks





Meirman

If emailing, please let me know whether
or not you are posting the same letter.
Change domain to erols.com, if necessary.



Similar thing happened to me when I purchased a used snowblower. Someone
had stripped the plug threads in the head, as I discovered when I tried
to start it up.

The most economical fix for me was to buy a new head, gasket and plug.
IIRC it cost me less than $15 for all. A helicoil kit or getting a
helicoil installed by a shop would have cost me more. G

Just my .02,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"