Sounds like the choke is not opening fully to me. Black smoke on your transom, or in the exhaust will be a dead give away for an overrich condition. <BR>Look at the top of the carb after the engine has reached close to operating temp. On a Holley, the choke butterfly is in a air horn that rises above the surface you mount your flame arrestor on. <BR>Once the engine is warmed up, that butterfly should be standing wide open. You should see it's edge, not the flat part. If it is not wide open you have either a bad power supply to the electric choke, or the spring inside the choke mechanism is worn out, and no longer responding to the resistance heat from the 12vdc wire that should force it to expand and open the choke. <BR>If this is the problem, you might be able to simply lock the choke valve open to get you by until you can confirm the power supply and/or get the parts for the carb. The choke mechanism is located in that round black plastic cover on the side of the carb. Loosen the three phillips screws that hold that cover on just enough so that you can turn the cover in either direction. One of thse directions, I think counterclockwise, will open choke up. Once open, tighten the screws back up. Your choke will no longer work, but you will eliminate the rich condition that is keeping your engine from running right. You will have to tickle and tease the throttle a little more to get her cranked up when she is cold. <BR> <BR>If not the choke, check the float levels to see if Mike's diagnosis is right. On the side of the carb towards both ends, you will find brass slot head screws a little smaller than a dime. Have s supply of rags nearby, and have a buddy ready to shut the engine off. Have your fire extinguisher nearby. Do this test on a cold engine, place a rag under the screws to soak up any fuel that might get loose. With the engine running, loosen one of these screws at a time, a little fuel should run out, if it pours out, you have a stuck or sunk float. You might get away with replacing the bad needle and seat, or the bad float, or adjusting the float level, but I would say rebuild time. <BR>If it is just below the level of the plug, and just dribbles out, it is close enough that it should not be your problem. <BR> <BR>If ya got no black smoke, make sure your fuel filter is clean, and your tank vent is clear. <BR> <BR>The last thing to check before popping the float bowls off are the idle air bleeds. These are very small holes that are down below the top of the carb, in both the primary and secondary venturi bores. They will lined up towards the metering plates. There will be four of them on each side of the carb. <BR>Grab a magnifying glass, and, with the engine off, makes sure these little passages are open. <BR>Some will be very, very small. They allow air into the emulsion system that, in essence, signals the fuel to transfer into the venturi and become emulsified so that the carb can send into the manifold controlling the mixture for the idle. Two of the holes will be larger.The larger of the holes are the high speed bleeds, they are most likley not your problem. If the bleeds are plugged up, you can tune on that carb til the cows come home and the engine will never run right. <BR>As an example, custom built high-perf racing carbs have screw-in bleeds, and you can literally have as much effect as a two-size jet change by tuning the bleeds. I have done it more than once at a track between rounds. <BR> <BR>Holleys are easy to get the right kit the first time if you can give the parts store guy the List number of the carb. This number is stamped on the outside of the metal riser that the choke butterfly is mounted in. <BR> <BR>Summit Racing sells holley's line of Marine replacement carbs, the small block Ford 600cfm units are around 450-500 bucks. <BR> <BR>The trick kit is listed at $79.88 If that carb has been on the boat since new, it is ready for a freshing up for sure. <BR> <BR>If you go that route, pay close attention to all the instructions in the kit, including those regarding the tightening down of the base to body gaskets and the float bowl screws. <BR> <BR>I cannot count the number of Holleys I have seen that people have ruined by overtightening the darn float bowl screws. It is very easy to warp the metering plates and even the main body of the carb by cranking these fasteners too tight. At that point, the carb is pretty much junk. <BR> <BR>If you decide to rebuild your Holley, I would strongly suggest buy a good book on the Holley carbs, and read it. You will be much more comfortable working on these carbs when you understand how they work. Summit Racing sells a book by Dave Emanuel called "Super Tuning and Modifying Holley Carburetors" <BR>It is $16.00, and worth it. Your buddies will be calling you the carb guru when you get finished...
|