I'm working on a Mercury 60 (06267531 - model 31502313 ?) that bogs down after about an hour or so of running. After sitting for a week, it starts fine and will run about 4k (under load) for about an hour, but then will start to bog down and die unless throttled back. Engine will run at around 2500 at half throttle, and when pushed above that engine dies. This also can happen after stopping the boat and trying to restart. Engine will rev with no load, but seems rough. Sometimes when in this condition, the throttle can be pushed WO and engine will run about 3200. I have sometimes had luck nursing the engine beyond half throttle if I play with the choke. I've even been able to nurse it back to full speed using throttle and choke, but this is not always the case. Engine will run at 2500 all day long at half throttle, but will idle maybe 10 seconds then die. Also low speed maneuvering is impossible as engine cuts out frequently.<br /><br /> Plugs have been replaced. Priming with bulb does not seem to help. Vented tank with no luck. Checked pickup and fuel line which seem to be OK. Replaced fuel and used dry gas to remove any water. I have also pulled plugs after engine runs this way, made sure they are clean and dry and let engine sit for an hour before restarting, but still will not run properly. <br /><br /> Any one have any advice on this? I'm thinking fuel due to the results with using the choke. Haven't replaced fuel filter yet - not sure that is the problem. Probably not ignition as it gets better when rich (using choke) and does not improve after cooling. Unfortunately I'm a bit marine engine challenged but good with auto engines. Any help would be appreciated.<br /><br />Thanks in advance!
