Corroded exhaust on Honda BF50

nexus6

Recruit
Joined
May 21, 2003
Messages
4
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
 

Skinnywater

Commander
Joined
Mar 7, 2002
Messages
2,065
Re: Corroded exhaust on Honda BF50

Are you using any extra-ordinary fuel or oil additive?<br /><br />Has anyone at Honda made any interpretation of the problem?
 

nexus6

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Joined
May 21, 2003
Messages
4
Re: Corroded exhaust on Honda BF50

No, nothing that I can think of.. The engine is running on Semi-Syntethic 10W-40 oil, and Swedish standard fuel (95 octane, lead-free)...<br /><br />Unfortunatly Honda doesn't seem to have any support or customer related divisions in Sweden. They just gives their authorized dealers as reference and they don't seem to have any support from Honda Sweden either..<br /><br />This morning I sent an E-mail to Honda UK and asked about this problem, so I think I'll just have to wait and see if they can give me any answer... <br /><br /> =(
 

nexus6

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Joined
May 21, 2003
Messages
4
Re: Corroded exhaust on Honda BF50

For those who are intrested:<br /><br />I've just got a respons from Honda regarding my corrosion problem. They told me to flush the engine with fresh water every time I've used it...<br /><br />I had to write them another question. I flush the water system regularly, but when the corrosion is in the exhaust channels, do they want me to flush them as well? What happens when the water reaches the cylinder head and cylinders? I don't think they can recognize my problem...<br /><br />Well, if I'll hear anything more, I'll post it...
 

nexus6

Recruit
Joined
May 21, 2003
Messages
4
Re: Corroded exhaust on Honda BF50

Just got another respons for those who are intrested... Nothing much, just<br /><br />"please fwd to P/E C/R"<br /><br />... wonder what they mean? Anyone have any idea?
 

Yepblaze

Lieutenant Commander
Joined
Jun 1, 2001
Messages
1,686
Re: Corroded exhaust on Honda BF50

P/E? - C/R? customer relations?. Sounds like they are taking some interest in your situation. <br /><br />Perhaps they might cover your parts cost "just because"
 

caribes

Recruit
Joined
Mar 13, 2014
Messages
1
Re: Corroded exhaust on Honda BF50

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. 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? 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?Would be very greatful if anyone could help me sort this out Thanks in advance,Anders Rand
I am running a BF90 on a support boat for my childrens sailing, so we do a lot of hours in it at not much more than idle speed. I am wondering if my problem of exhaust fumes coming into the boat from the exhaust outlet holes in the rear of the engine is related to corrosion in the exhaust channels?
 

MattFL

Master Chief Petty Officer
Joined
Oct 20, 2010
Messages
827
Re: Corroded exhaust on Honda BF50

Water is used to cool the exhaust, so parts of the exhaust will get salt water during use. You should flush with fresh water after every use in salt. It sounds like they need to use better materials too, but definitely flush after every use in salt. flush by running on the muffs or in fresh water.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,500
Re: Corroded exhaust on Honda BF50

I am running a BF90 on a support boat for my childrens sailing, so we do a lot of hours in it at not much more than idle speed. I am wondering if my problem of exhaust fumes coming into the boat from the exhaust outlet holes in the rear of the engine is related to corrosion in the exhaust channels?

That thread is more than ten years old. probably need a new one, since you have a different item to discuss anyway...
 
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