01262 0 Report post Posted July 22, 2011 My boat is a 01 262 cruiser with a 250 5.7 merc. full injection system, I purchased the boat three years ago with 50 hours on it. The engine has always burned alot of fuel, to the point that it would apear to smoke when running. The back of the boat gets black under the swim platform from the engine exhaust. I can clean it in the morning, then run it for two days and it will be black again. I was told to try a new plugs, cap and rotor but it is not missing. Someone else told me to replace the oxygen sensors. This may be the problem, but I do not know where they are or what that entails. Has anyone else had this problem and what fixed it for you? A local marine mechanic told me to put a fuel cleaner into the gas (Techron made by Chevron) I have been using this all summer without any change. Share this post Link to post Share on other sites
snosptz 0 Report post Posted July 23, 2011 My boat is a 01 262 cruiser with a 250 5.7 merc. full injection system, I purchased the boat three years ago with 50 hours on it. The engine has always burned alot of fuel, to the point that it would apear to smoke when running. The back of the boat gets black under the swim platform from the engine exhaust. I can clean it in the morning, then run it for two days and it will be black again. I was told to try a new plugs, cap and rotor but it is not missing. Someone else told me to replace the oxygen sensors. This may be the problem, but I do not know where they are or what that entails. Has anyone else had this problem and what fixed it for you? A local marine mechanic told me to put a fuel cleaner into the gas (Techron made by Chevron) I have been using this all summer without any change. I have a 2000 - 262 cruiser with the same motor except it is not fuel injected. In have had a simular problem except it took many hours before the back of the boat gets black under the swim platform from the engine exhaust. I noticed that I was burning 1 quart of oil in 100 miles or about 8 hours. I pulled the spark plugs to look at how they were burning. I found that 2 plugs were so fouled that 1 of the 2 plugs I could not even see through the gap in the plug, the other was bad but not as bad. This went on for 2 years, each year the mechanic replaced the intake gasket and plugs. The boat run good for most of each season but by the end of the season the same condition was back again. After 2 years and 2 intake gasket replacements they finally dug deeper. Now this year they have removed the head on one side and found that 2 valves were not sealing so they did a valve job on one side of the motor. I expect this to work and so far no black engine exhaust and I did pull the 2 plugs and they look good. hope this helps. Captain Sapphire Share this post Link to post Share on other sites
