carburetion problems

[betayv]

hi guys 1987 searya with 5.7 engine carburetor was rebuild by a professional shop, boat starts and I see a lot of black smelley smoke coming out of exhaust, rev in idle are 700-800, with the prop egaged in forward is 675-750, any suggestion?, new spark plugs, new wires, new cap, I just have the boat couple of motnhs ago.

 

[alldodge]

hi guys 1987 searya with 5.7 engine carburetor was rebuild by a professional shop, boat starts and I see a lot of black smelley smoke coming out of exhaust, rev in idle are 700-800, with the prop egaged in forward is 675-750, any suggestion?, new spark plugs, new wires, new cap, I just have the boat couple of motnhs ago.

Black smoke means your running rich, and need to check the carb. Is the choke plate opened all the way when warm? If it is then shut the engine off and see if you see fuel dripping. My first thought is if it isn't the choke then the float level may not be set correctly or there is a speck of something in the needle seat

 

[JustJason]

Low compression is the #1 cause of black smoke. Run a compression test.

 

[narblr]

Check the carb for a sticking choke and properly set up needle valves, too little air will cause black smoke

 

[GA_Boater]

betayv - Do you have a Mercruiser or a Volvo-Penta? You started topics in both forums.

 

[betayv]

choke plate?, can you help me with that I don't think this carburetor have a choke.

 

[betayv]

sorry guys is a mercruiser thanks for the help.

 

[alldodge]

choke plate?, can you help me with that I don't think this carburetor have a choke.

There should be a plate which is on the very top of the carb throat. Don't know if you have a 2 or 4 barrel carb. The choke plate in the pic below is closed over the front 2 barrels of the carb. The carb is actuated from linkage found on the carb and an electric heat element on the side of the carb. The plate you see closed in the pic should be straight up and down when the engine is warm.

http://www.ebay.com/itm/Holley-0-80...Parts_Accessories&hash=item41887091be&vxp=mtr

 

[GA_Boater]

sorry guys is a mercruiser thanks for the help.

Fixed.

 

[betayv]

is a 4 barrel, I don't see any electric heat element on the carburetor, but that plate is closed.

 

[NHGuy]

Does the choke spring back closed if you open it with your finger? It should stay closed when the motor is cold. If you have the early style there could be a choke link on the starboard side of the carburetor. It's supposed to attach to a heat actutated spring on the intake manifold.
If it does not open when warm it may need to be connected up.