Jets ?

josht52302

Cadet
Joined
Jul 31, 2013
Messages
11
I have a 1963 mercury 650, 4 cylinder, 2 stroke. I live at high elevation and the motor seems to be running really rich. It pooches out when you give it throttle. From what I've gathered the idle mix is adjustable, but the high speed jet is not. Is there replacement jets ? Is there another way to lean this pig out? And when I do get it leaned out will my oil/fuel mix need to be changed?
 

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: Jets ?

Here is a link to the condensed version of the Clymer manual. Download it soonest to your computer as the link is short lived.

Small Engine Repair Reference Center Home: MERCURY - MERCURY FOUR & SIX CYLINDER MODELS (1955-1965).

See page 104, Tillotson Carburetors.

You haven't included your engine s/n but if you are sure it is a 1963, here is a link to the parts listing:

MERC 650 - Mercury, Mercruiser, Force, etc. Parts Lookup

See item 29 under CARBURETOR ASSEMBLY for decreasing jet sizes.

Gerry
 

josht52302

Cadet
Joined
Jul 31, 2013
Messages
11
Re: Jets ?

I found jets @ seawaymarine. I think .067 will work. I've checked the serial# its definitely a '63. $35 for the jets,$35x2 for the carb rebuild kits. Hopefully they make a difference. I'll find out when they get here.
 
Last edited:

Dave1027

Lieutenant Junior Grade
Joined
May 25, 2010
Messages
1,078
Re: Jets ?

I found jets @ seawaymarine. I think .067 will work. I've checked the serial# its definitely a '63. $35 for the jets,$35x2 for the carb rebuild kits. Hopefully they make a difference. I'll find out when they get here.

Ouch. $35 for a tiny amount of brass? That's robbery. I wonder if Holley makes some jets that fit?
 
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