50 HP 4 cylinder merc ??

S

sledstew

Petty Officer 2nd Class
Joined
Jun 16, 2005
Messages
100
Motor runs great at Idle but when I get it around 1/2 to 3/4 throttle it pops and carries on and I noticed that the head gasket is leaking when it pops. Why would air pressure be coming popping out of the head gasket since this motor just has a water cover not a removeable head.??


My theory? Thinking maybe the exhaust is backing into cooling system ,anyone have any idea what is causing this. Carbs may need to be cleaned also thats why its popping.
 
C

cannonford57

Petty Officer 1st Class
Joined
Mar 5, 2008
Messages
353
Re: 50 HP 4 cylinder merc ??

you have answered your own question stew....how can it be leaking around the HEAD gasket when it doesent have a HEAD gasket.just my opinion of course.
 
AMD Rules

AMD Rules

Lieutenant Commander
Joined
Sep 23, 2004
Messages
1,707
Re: 50 HP 4 cylinder merc ??

Suggest you pop that water cover off and have a peek.

Have you done compression test yet ?
 
S

sledstew

Petty Officer 2nd Class
Joined
Jun 16, 2005
Messages
100
Re: 50 HP 4 cylinder merc ??

compression test is good, looked behind water cover and it looks good, couldnt see any fractures at all.
 
zinc

zinc

Seaman Apprentice
Joined
Jun 8, 2009
Messages
40
Re: 50 HP 4 cylinder merc ??

Just an observation,
water is leaking around near the sparkplugs,
im assuming they are getting wet and the high voltage to fire them
is instead being grounded out by the water, which would cause a miss
fire....your popping noise.
Just my opinion.
 
B

blared

Cadet
Joined
Jun 3, 2009
Messages
23
Re: 50 HP 4 cylinder merc ??

I dont know what year your outboard is but it might be leaking from the exhaust plate gaskets too ... it's just near the head.
 
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