craze1cars
Lieutenant Commander
- Joined
- Dec 26, 2004
- Messages
- 1,822
1992 Mercruiser 3.0L 115 hp, 2bbl Mercarb model 9562-2. First carb rebuild since new.
Bought a Sierra rebuild kit here on Iboats, and all is going well. Gutted and cleaned, just getting to reassembling the float and needle valve and I'm in a quandry. Here's 2 specific questions that I feel need some build-up to accurately describe:
1. Float level adjustment...instructions in the kit say to measure from the "toe" of the float to the gasket. Well the toe itself is about 10 to 12 mm thick (depending on how you measure from rounded corners.) There are also two dots on this toe spaced 8 mm apart. I don't know where to measure the float from. I presume one of those dots is my measuring point? If yes, which? The dot closest to the gasket, or farthest from the gasket?
2. Needle choice. My kit came with 2 types of needle/seat assemblies, one uses a solid bar in the needle, the other uses a spring and narrower bar in the needle. Instructions say either can be utilized for my 9562 carb. Originally mine had the solid needle....but fine print in the instructions says "on 4 cyl engines w/flood or rough idle, if all componants and specs are OK, may be necessary to change to the spring loaded needle and seat." So...is the spring loaded needle indeed a better option? Should I use it instead of reinstalling the OEM solid needle? I do indeed experience some occasional minor flooding while engine is warm, and idle is indeed a bit rougher than I like, but it isn't a huge problem.
To further complicate things, it says I should have 10 mm float level with solid needle, 14 mm with spring needle. I tried both just for giggles...the solid needle gives a MUCH larger float reading than the spring...which is the opposite of what I would expect based on the above specs. So that confused me even more on how to measure the float level.
Before anyone asks, yes I have very carefully set base timing by disconnecting advance, checked for proper operation of advance, new cap/rotor, properly gapped new plugs, new wires, set idle mixture and speed, compression tested 140 to 145 on all cylinders, etc. Did all that stuff at the beginning of last year and it all helped, but didn't fully cure all my occasional minor flood/bog/stumble at idle ills. That's why I'm going through the carb now...plus the simple fact that it's over 16 years old and never been cleaned.
Any guidance is greatly appreciated. And any other rookie/unwritten tips from those of you with enough experience to know the quirks of these motors and how to tune these carbs, my ears are open...this is my first boat carb rebuild, though I've done many other varied vehicles over the years.
If this means anything, it has 145 jets installed.
Thanks as always!
Bought a Sierra rebuild kit here on Iboats, and all is going well. Gutted and cleaned, just getting to reassembling the float and needle valve and I'm in a quandry. Here's 2 specific questions that I feel need some build-up to accurately describe:
1. Float level adjustment...instructions in the kit say to measure from the "toe" of the float to the gasket. Well the toe itself is about 10 to 12 mm thick (depending on how you measure from rounded corners.) There are also two dots on this toe spaced 8 mm apart. I don't know where to measure the float from. I presume one of those dots is my measuring point? If yes, which? The dot closest to the gasket, or farthest from the gasket?
2. Needle choice. My kit came with 2 types of needle/seat assemblies, one uses a solid bar in the needle, the other uses a spring and narrower bar in the needle. Instructions say either can be utilized for my 9562 carb. Originally mine had the solid needle....but fine print in the instructions says "on 4 cyl engines w/flood or rough idle, if all componants and specs are OK, may be necessary to change to the spring loaded needle and seat." So...is the spring loaded needle indeed a better option? Should I use it instead of reinstalling the OEM solid needle? I do indeed experience some occasional minor flooding while engine is warm, and idle is indeed a bit rougher than I like, but it isn't a huge problem.
To further complicate things, it says I should have 10 mm float level with solid needle, 14 mm with spring needle. I tried both just for giggles...the solid needle gives a MUCH larger float reading than the spring...which is the opposite of what I would expect based on the above specs. So that confused me even more on how to measure the float level.
Before anyone asks, yes I have very carefully set base timing by disconnecting advance, checked for proper operation of advance, new cap/rotor, properly gapped new plugs, new wires, set idle mixture and speed, compression tested 140 to 145 on all cylinders, etc. Did all that stuff at the beginning of last year and it all helped, but didn't fully cure all my occasional minor flood/bog/stumble at idle ills. That's why I'm going through the carb now...plus the simple fact that it's over 16 years old and never been cleaned.
Any guidance is greatly appreciated. And any other rookie/unwritten tips from those of you with enough experience to know the quirks of these motors and how to tune these carbs, my ears are open...this is my first boat carb rebuild, though I've done many other varied vehicles over the years.
If this means anything, it has 145 jets installed.
Thanks as always!
