1974 Johnson 6HP outboard running again! Sparkplug repair juryrig + late Spring
Channel: bellarmine33
Date: 2013-04-27

Finally got my little ole' 6-horse running again!  Juryrig stripped spark-plug thread repair, but it works, watch it and see! ---------- Also a tour of our super late Spring this year (April 25 2013), ice, snow and rain, and still super muddy road.  Last year the ice was all gone end of March, and our road was all dry mid-April.  Water-level's also over a foot higher than usual, they always dam it up Spring, and cause havoc between floating docks and the ice and such.......:^)

Anyway, about the motor, it's a 1974 6hp 6R-74C short-shaft.  Had it as long as I can remember, my Dad bought it in the 80's from a resort on the lake.  Had lots of adventures with it, only motor I knew until driving the 30HP Javelin (see my earlier videos).

Few years back I spent some money tuning it up, carb kit, points and condensers, oil seal, ran pretty good.

Then, the dingy it was on sank on me, just after I tuned it up too!  This was a few years back, and it wouldn't run all too good after that (no surprise).  I think the coils were done in, they were cracked to begin with.

So replaced the coils, and tried those little electronic ignition modules you can get for a lawn mower engine, didn't work too good, weak spark.  My marine mechanic told me these marine engines need a stronger spark than those little modules provide.  So I went back to the points, got real strong spark for the first time!

However, in the meantime, I had worn out the spark plug threads in trying to get it to start before.  My Dad told me (a bit late.....:^), that they were weak, so that was that until I got a new cylinder head.

Then over the winter I got this idea.  I had these two Champion L78C plugs lying around, slightly longer thread than the stock J6C/J6J plugs.  I gapped them to .030", then just screwed them into the soft-as-butter aluminum head, seated and tightened down fine!  No more hissing steam-engine leaks lol.  The length was close, so no danger of hitting the pistons or anything.  Maybe this'll help someone in an emergency with stripped plug threads........:^)

Still need to install a new impeller and seals in the lower unit, but at least it's on the lake again, instead of moldering in my basement!

For spark plug specs, download this handy PDF:
  http://www.hrpworld.com/client_images/ecommerce/client_39/products/pdf_1395_1.pdf
Also these sites:
  http://www.sparkplug-crossreference.com/convert/CHAMP_PN/J6C
  http://www.sparkplug-crossreference.com/convert/CHAMP_PN/J6J
  http://www.sparkplug-crossreference.com/convert/CHAMP_PN/L78C
  
The boat is a 1965 Viking 14-foot fiberglass runabout.  Even have the ownership papers too. 

Thanks for watching!

bellarmine33