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Vacuum leak. common locations?

C

Canadianwalleye

Regular Contributor
Took out my 78 115hp Evinrude. Still bogs at idle. Seems to not be as bad as it was.
while out on the water I notice that the primer bulb connections on both ends was slowly slightly leaking. I took some extra zip ties I have in the boat and tightened them up. Started the engine and it seemed to run better. I’ve almost got it dield in to perfection but still have a slight cough/bog.
Where are the common air leak areas I should check?
Are there any places not obvious?
Thanks everyone.
 
Is it hesitating when you throttle up? I would say start from the beginning give us your compression numbers engine cold. Start with a fully charged battery and all plugs removed. Test it three times 1-4 1-4 1-4 and write the numbers down and take the high number for each cylinder. Do a open air spark gap test the spark must jump a 7/16 gap with a crisp blue snap. Get back with that info then you canmove on to fuel.
 
Doesn’t seem to hesitate when I throttle up no. Going to do a compression test this weekend. I will do it the way you suggest. How do I test open air spark gap?
 
The best is with a spark gap tester but you can stick a screwdriver in a plug wire and hold it 3/8-7/16 away from a good ground. Your local auto part store should have them.
 
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