You haven't got on my bad side. I am just a cranky old man that has been around boats for more than 50 years. The reason the exhaust gets darker as the engine speed increases is as you are increasing the throttle the more unburnt fuel you are putting though the engine. Do you know when that prop was put on the boat? Did you do a sea trail when you bought the boat? If you did have a sea trial was the engine ran at full throttle for 5 to 10 Min's. When you bought the boat did you have oil analysis done to check for particulates and contaminates in the engine oil including unburnt diesel?
Last edited by bubb2; 05-29-2011 at 09:37 PM.