150HP V6 Mystery Chatter...

deviljohn

Seaman Apprentice
Joined
May 2, 2008
Messages
38
Have: 1994 150HP V6 60 deg loop charged engine

model# E150GLERA

Engine is running normal, however there is a "mystery" chatter that becomes audible around 2k rpms. Chatter is erratic and not rhythmical...can not hear it at idle in water or on muffs...

Had a mechanic bud river test w/ me and he deduced Lower unit starting to go bad...swapped a new "used" lower unit in...same chatter.

Wondering if perhaps chatter is coming from a bad reed valve. have checked flywheel and swapped out fuel pump/vro (vro is disabled w/ premix on this motor)

I realize that reed chatter is normal on the engines when backing off of throttle...thinking of putting boyesens in, but before said expense wondering if anyone has any ideas on this one.....thoughts??

tx in advance
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 150HP V6 Mystery Chatter...

Make sure you have Champion plugs, probably the QL77JC4 would be a nice choice with todays fuel. Then make sure you have fresh (30-40 days old is not fresh) 87 octane fuel.

The 60* V6 will make a knocking sound on a quick decelleration. The engineers cal it "de-cell knock". Makes a horrible sound but doesn't really hurt anything.
 
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