1981 Johnson 175hp check valve replacement for cylinder drain

dalejunior91

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Mar 28, 2015
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Hi, I can't figure out where the cylinder drain valve is located? I was wondering if there is 1 for each cylinder or just one for all 6?
My spark plugs have been fouling out. I had the carbs rebuilt and it didn't fix the problem. So I did some reading online and it said that it was either the Carbs or this mysterious Cylinder drain check valve. My motor seems like it has been running rich on idle and at high RPM's.

Thanks in advance for the help
 
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racerone

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Dec 28, 2013
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Yep folks usually pick on the carburetors to start repairs.--Hopefully it did not cost too much.----Report results of a compression test.----Are the thermostats installed ??
 

boobie

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Nov 5, 2009
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You're probably talking about the recirculation valves. There are six on your motor, one for each cylinder. If they're not working you will foul plugs, There's a test procedure in the service manual.
 

dalejunior91

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compression on the motor cylinder #1 85 #2 84 #3 86 #4 86 #5 83 #6 83, Im also mixing my fuel 50 to 1, the water thermostats are in and working. and it wasn't to bad.

Boobie, I saw those, I received the check valves in from iboats and they are bigger than the brass pieces them selves that connect into each cylinder. Thats why i wasn't sure. Service manual states that i need to use a syringe and rubbing alcohol to test them. Sound correct?

thanks again
 

boobie

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Dale, the manual is correct. And the valves are in the intake manifold.
 
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