Where to buy outboard sparckplugs

J

john m

Well-Known Member
Joined
11 Feb 2006
Messages
508
Visit site
I want to buy new plugs for my 15hp Johnson I think it's late eighties can you get them from car autoshop or do they have to be from a dealer
 
Last edited:
No you are unlikely to get the correct plugs from a car parts shop.

Champion plugs are recommended. A late eighties engine will have CD ignition and if suppressed plugs are used they should be inductively suppressed not resistor plugs.

Any Johnson 15hp from 1977 to 1992 uses either Champion QL77JC4, gapped at 0.030", or L78V Surface Gap plugs

(If you do not need a suppressed plug then L77JC4 will do).

The NGK equivalent of QL77JC4 is BZ7HS-10, of L77JC4 is B7HS-10 and of L78V is BUHW-2 But only use the NGK plugs if you really cannot get Champions.

Oakley marine, Willsmarine or any other Evinrude/Johnson dealer should be able to supply the correct plugs.

Also http://www.sparkplugs.co.uk/. (£2.88 + VAT each for QL77JC4)

I would not use the surface gapped plugs unless you will be running at constant high speeds.

BTW the correct fuel mix is 50:1 even if it has decals that say 100:1

PS. the plug numbers I quote (QL77JC4 and L78V) are the latest recommendations. They may not be the original numbers which are still listed in the parts catalogs
 
Last edited:
Is that a particular foible of the outboard? In the classic car world it's generally NGK above all else now - and the LPG conversion in my DS was only warrantied if I used NGK plugs in it.
Click to expand...
It is the manufacturers recommendation!
It is said that Johnson and Evinrude engines have been designed around Champion plugs. AC and Autolites were recommended for some at one time and NGKs are recommended for a very few of the recent rebadged 4 strokes.

I suspect one issue is the requirement peculiar to OMC engines that the CD ignition must use inductively suppressed plugs and not resistor plugs. I think NGK have only relatively recently started producing them.

As an academic you might find http://members.iinet.net.au/~pauldawson/iame26-spark-plugs.PDF interesting

FWIW I have a set of Champions ... the originals ... and a set of (unsupressed) NGKs for my Evinrude. I notice no difference between them.
 
thanks for all help i will get them orderd tomorow as the engine cuts out when accelerated unless i press the choke just trying to elimanate things easy stuff first
 
New plugs always a good idea but if you can keep it going by operating the choke the problem is very likely to be a dirty carburettor.


BTW if you quote the model number which should be on a plate on the transom bracket It will be possible to tell you the exact year of manufacture
 
thanks vics i will try cleaning out the carb next time im at the boat {hopefully the weekend} and i will post back
 
Properly cleaning a carb means a complete strip down. making sure all passages are clear ( that may mean removing any lead shots that blank of the ends of some of them ) and rebuilding with a "carb kit"

You will find an exploded diagram of your cab in the parts catalog. Go to
http://shop2.evinrude.com/Index.aspx?siteid=1&catalog_id=0&s1=0f17289cec9be4e6d168842b72241fbf
Then find you engine by make, year, hp and model number and select carburettor.

You can get the year from the model number. Ignore the last letter, then the previous two give the year according to the code

I=1,N=2,T=3 etc for the letters of the word INTRODUCES to E=9 and S=0

So the year letters for an 87 model will be CU.

You will also find most of what you will ever need to know about the 15hp models at
http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm
 
You must log in or register to reply here.

Other threads that may be of interest

M
Raymarine Plotter Trackpad
Replies
2
Views
159
laika
laika

Share this page

Top