Rebuilding carburetors on a 1978 55HP 2-Cyl

Joined
Jun 5, 2004
Messages
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I have a 1978 Johnson 55HP 2-Cyl Model# 55EL78S<br /><br />I'll give as much info as I can, but I really only have one (2) questions. <br />1. Was my process thorough?<br />and<br />2. Did I leave any parts out?<br /><br />My problem is this:<br /><br />I recently rebuilt my carburetors. They work great at all speed except idle.<br /><br />I have learned from some knowledgable folks on this site that my carburetors have fixed jets, therefore replacing the jets (which I don't think is the problem) is the only way to adjust the carburetors at all.<br /><br />I went back and looked at the parts left over from the rebuild kits. There are quite a lot of them. When I originally put the kits in, I:<br /> <br />1. Removed the 2 jets/orifices, <br />2. Removed the entire needle valve/float assembly. <br />3. I then cleaned (soaked overnight) the entire carburetor bodies using carburetor cleaner. The next morning I made sure the holes on the brass tubes, as well as the brass tubes themselves, were all clean and clear, as well as the passageses into which the jets/orifices were screwed into, and generally made sure the entire carburetors were clean.<br /><br />I then reassembled the carburetors. <br /><br />1. I installed the new float and needle valve assembly, taking care to set float parallel with the carburetor body when inverted. <br />2. I screwed tight the high-speed jet into its passage in the bottom of the float bowl. Adding the exterior bowl screw completed the bowl. <br />3. Using the new float bowl gaskets, I tightened the float bowl screws.<br />5. I then screwed in the idle jet/orifice in the top center of the carburetor until it was tight, and screwed in the cover-screw using a new washer.<br />4. I installed the carburetors using the new carburetor to manifold gaskets.<br /><br />So, other than the parts that made up the needle valve assembly and float, only two small washers, the bowl gasket, and the manifold gasket were replaced.<br /><br />There are lots of partsleft over from the kit. The kit came without instructions; however, I do have a Clymer manual to reference (not the easiest thing to read). <br /><br />After reviewing my process, does this sound like I replaced everything I was supposed to? I read a new post today that mentioned a "jet seat made of plastic" that one guy was having problems with.<br /><br />Was my process thorough? <br />Did I leave out any parts, or did I miss parts that should have been changed?<br /><br />Thanks,<br />Eric
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
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10,161
Re: Rebuilding carburetors on a 1978 55HP 2-Cyl

Eric...most kits cover more than one carb. So left over parts are expected. Sounds like you did a through job.<br /><br />What you probably need to do is do a sync and link. This puts the timing and throttle plates in time....ie...at a certain time, the plates start to open. Don't know if the generic manuals cover this or not. But it's important to do. It would probably also help the low end idle.
 
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