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How do I put in carburetor check valves??

R

rayban

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My friends '98 johnson 115hp is running badly when hot. After some troubleshooting and tests that led to nothing we decided to remove and clean the carburetors.

While doing so we noticed that four hidden check valves seems to be placed differently on stb and port side.

Question is: Is this correct?
 

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Those are part of the recirculation system. They keep the unburned fuel moving around the system until the next time you run fast enough to evacuate it in the the combustion chamber & burn it. If blown open they usually cause the engine to lean spit at idle just like an intake leak. If plugged then the engine will load up after prolonged idle. You can clean them with a blast of brake clean. A piece of small fuel hose place up against the face of the valve will let you see if they are checking. Just blow & suck to see if they are working. Worth checking as they are expensive to guess at?
 
Pry the old ones out and press in the new ones. Replace them all. Too much work to risk leaving a bad one in there.
 
I also noticed that the bowls or float chambers has lost their shape. Sad as my friend had them replaced last year. At least thats what the shop mechanic said he did. Guess you could expect them to last at least more than a year... Doh!
 
The original bowls did warp, but I have seen them last 20/30 years. I'm sure they were seeping before that? Some of what happens has to do with the way they are installed. When put on new they need to be tightened in a crisscross pattern. Keep the pressure even on all corner. They can be over tightened.
 
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