1973 Johnson 6HP - Sputters at WOT.........

Walkwolf

Walkwolf

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Joined
Aug 17, 2012
Messages
7
Hi all. I have a 1973 Johnson 6HP that starts, idles and seems to run
ok, but occasionally sputters or hesitates - especially at WOT.
It sat unused for a couple of years before I had it seviced
with a new impeller and plugs.

Guessing it might be the carb or perhaps the coils ?
Any help would be appreciated.........



Regards,





Steve.
 

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emoney

emoney

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2,551
Re: 1973 Johnson 6HP - Sputters at WOT.........

Check the fuel system (lines, etc.) Welcome to iboats.
 
Walkwolf

Walkwolf

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Joined
Aug 17, 2012
Messages
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Re: 1973 Johnson 6HP - Sputters at WOT.........

emoney said:
Check the fuel system (lines, etc.) Welcome to iboats.
Click to expand...

Hi emoney - Thanks for the reply. The line and tank both work well
with another motor I have ( 1980 Evinrude 7.5 ).
 
D

Daviet

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8,958
Re: 1973 Johnson 6HP - Sputters at WOT.........

With it setting for a couple of years, I would start with a good carb cleaning paying attention the the high speed orifice, make sure it is not restricted or plugged.
It might be that you have a coil breaking down under load when it is running at high speed, you could check it with a self powered timing light. Just check eack plug wire and see if you have a constant pulse on each plug when it is sputtering.
 
B

boobie

Supreme Mariner
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Nov 5, 2009
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20,826
Re: 1973 Johnson 6HP - Sputters at WOT.........

When you say "sputter" I'd have to say a carb prob with it flooding over at high speed.
 
Walkwolf

Walkwolf

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Aug 17, 2012
Messages
7
Re: 1973 Johnson 6HP - Sputters at WOT.........

Thanks, Daviet and Boobie. Lol - 'stuttering' might be a better word/term for what it's doing !
I'll check both. I've read that varnish can build up in the carb over time, and also that
a cracked coil may cause power loss ( arcing ? ). It is just shy of 40 years old
and been with me less than 10% of that time, so I really don't know
all of it's history.

Maybe a dumb question - does it make any difference whether a motor
is stored upright on a stand, or laying on its back.........?
 
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