I have a 1997 Honda BF50 on my boat. Last season I noticed the engine was burning oil and thought I had to do a small overhaul (changing rings and bearings). When I disassembled the engine I saw something funny. <br /><br />All the exhaust channels through the engine block, oil sump and adapter plate between the engine and the sump was corroded so bad that I now have to buy a new sump and adapter plate (setting me back a minor fortune) as well as weld the engine block. My question is: Have I been running on the wrong fuel or something or why does the exhaust channels corrode so bad? Has any other Honda owner noticed this? <br /><br />The funny thing is that the engine has only been used for five seasons, and in Sweden a summer season only lasts for about 3-4 months. The engine shouldn't be that way in only five years, right? I'm sure I don't have a anode problem because the rest of the engine is fine, and why does the corrosion only attack the exhaust channels and not the water channels where the salt water is?<br /><br />Would be very greatful if anyone could help me sort this out !<br /><br />Thanks in advance,<br /><br />Anders Rand