71 Evinrude normal compression?

[John Lapic]

I’m sure someone knows what compression I should be carrying on my 71 18 hp Fastwin. I measure 89 and 91 psi but don’t know what the specs are. It’s running rough and I’ve changed plugs and have a good 5/16 spark, soaked the carb but am doing that again, adjusted the low speed till it started coughing then opened it up 1/4 turn and still getting a rough idle. Also the primer bulb doesn’t firm up so I suspect the bulb may be bad? Hoping someone can give me some insights. Thanks

 

[racerone]

Check fuel pump diaphragm.---Might be ruptured.

 

[Crosbyman]

also check the float/needle operation should work like your toilet bowl...stop when full ;-)

if the bulb does not firm up the fuel is leaking somewhere. Either back down the tank if the check valve does not seal properly in the bulb (try another one) or the inlet needle does not seal. as suggested a bad diaphragm in the pump would also let fuel drain out into the crankcase.