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89 20hp mercury

Relax

Relax

New member
I Love my Mercury and I'm investing in it. The outboard is Hard start, runs rough, replaced coils, waiting for carb kit, I see light through 14-16 reed valves (on order waiting for them) 115 compression on both cylinders, new impeller kit, cant wait to put it all together. Does any body have the specs for the timing or anything else you may think I would need to make this 36 year old be great again. Canadian mercury 20 hp 0A743033 also uses NGK BUZHW Surface gap plugs. I don't know if I can use the J plugs or not.

Thanks in advance if you can help
 
Thanks for the advise, what do you think about the J plugs. When I look up my 20hp it says 1986 to 1989 uses the surface gap plugs that were made for the hight rpm's. I just put around and fish :)
 
flyingscott said:
There is a service bulletin on those motors for the spark plug.
Click to expand...
Thanks Flyingscott, do you have a copy of the bulletin as I wasn't sure if the J plug would be too low and hit the pistons. I got my carb kit and back together and I'm just waiting for the Boyesen reeds kit (5 more days they say) Post seems slow at the moment. Just want to get out and fish
 
Do I have to use a special spark plug wire on my merc 20hp. I should change them as they are the originals over 30 years old and look it.
can I use a normal car or truck plug wire. way cheaper
 
No modern automotive wires, they have spark suppressant materials as a conductor. You need a copper core wire and not a silicone/carbon core. You can get these at the small engine shop or even the auto parts stores.
 
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