oil deposits in carby

tony murray

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Joined
Jan 7, 2009
Messages
19
I have a 70 hp 3 cyl merc 83 model
iv just had both carbys and fuel pump serviced all new gaskets and seals used
the fuel pump had new check valves and as per q.silver memo..a spring and cap were added.
the carbys had new inlet needles and idle mixture srew and spring again new gaskets used.
now after a run heavy oil deposits sit around the venturi jet and in the carby body.
can any one help?
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: oil deposits in carby

What premix ratio you using?

How many turns from seated are your idle AF screws?

"Spring and cap added" (in fuel pump?) "as per a Quicksilver memo"? Explain further, never heard of that.

New inlet needles in carb bowls...were matching new seats installed too? New needles have a rubber tip, seats must be replaced to match (i.e., new needle plus old seat=no work)
 

tony murray

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Joined
Jan 7, 2009
Messages
19
Re: oil deposits in carby

premix.......i mix all fuel in a container prior to filling the tank to ensure a good mix.............50.1
 

tony murray

Cadet
Joined
Jan 7, 2009
Messages
19
Re: oil deposits in carby

What premix ratio you using?

How many turns from seated are your idle AF screws?

"Spring and cap added" (in fuel pump?) "as per a Quicksilver memo"? Explain further, never heard of that.

New inlet needles in carb bowls...were matching new seats installed too? New needles have a rubber tip, seats must be replaced to match (i.e., new needle plus old seat=no work)
hi hope this helps!
the af screws were tightened to full then back off by two turns.........the inlet needles were replced along with new copper washers.
the spring and cap in the fuel pump are "raised caster pad and spring in the pulse chamber" my original never had this and its recommended by mercury upon o/h p/n 99523a1
mercury also recommend removing and not replacing the filter screen inside thefuel inlet.............................would any of these be causing the oil deposits? too much pressure perhaps?
any help would be so good
thanks
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: oil deposits in carby

Everything sounds good to me; maybe try turing the A/F screws in a quarter to half turn, with freshly done carbs and warmer weather you may be too rich at idle.
 

tony murray

Cadet
Joined
Jan 7, 2009
Messages
19
Re: oil deposits in carby

Everything sounds good to me; maybe try turing the A/F screws in a quarter to half turn, with freshly done carbs and warmer weather you may be too rich at idle.

thank mate......I will try this soon............my main worry was that it was terminal, "need new carbs" etc, too!!! expensive over here.
 
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