Hi, hoping to get some advice from all the knowledgeable folks on this forum. Been through a lot lately with my Honda 2003 BF200A3 - will try to explain everything and then hoping for some advice on next steps.
Engine/boat (21' Trophy) are new to me this year. Previous owner claims light use, only about 400 hours on motor, although I did not verify this (yeah yeah I know...). Judging by state of motor, how it looks internally, etc, seems to back up low hours.
I had used the motor for maybe 20-30 hours this year before going on an overnight trip where it died and would not start. Did not notice any issues up until this point, it maybe did not start right away on first spark but it started every key turn. On this trip we made it to the dock and then I went to move the boat to a new spot the next morning and it would not start - seemingly turning over but not catching. Went through everything I could at the dock, and fairly confidently eliminated any electrical issue up to the plugs - lots of juice in the batteries. No MIL / buzzer codes. Seemed to be a fuel issue so I thought maybe fuel pump and we had to be towed out of there.
Took it to a local Honda marine mechanic, wanting to get it quickly repaired and thinking it was something simple. Dumbly I had never actually compression / leak down tested it, but he proceeded to do that and found very poor results, plus rust on the plugs. Now pointing towards water getting into the cylinders. Compression results: #1: 140 psi; #2: 185 psi; #3: 150 psi; #4: 150 psi; #5: 180 psi; #6: 130 psi. Leak down loss results: #1: 70%; #2: 46%; #3: 38%; #4: 70%; #5: 50%; #6: 60%.
Pretty dismayed at this point with these terrible leak down results, he pointed towards pretty bad options financially from either scrapping the engine to cylinder boring, etc. From a financial standpoint I really couldn't afford to scrap this engine or pay someone huge cash to work on it so decided to go the DIY route and tear it down with an eye towards sending the heads or block to a machine shop, to keep things as cheap as possible while still recovering the engine.
So with shop manual in hand I began and have basically completed a tear down of engine to the point of getting the cylinder heads off (but block is still on the mount). What I found ...
- First big clue was the presence of what looks like significant amounts of water in the oil - the drained oil, the leftover oil in the pan, and the filter; milky/chocolate shake look, and very sludgy residue left in pan / filter - seems water definitely mixed with oil
- Also found what looks like white grease on the bottom of mount / top of oil pan - not sure if that's important
- Accessory components and shape overall of engine look pretty great - much better than what I've seen in some threads here, including passages/pipes, thermostats, block, manifolds, etc
- Very similar symptoms and clues as this Corrosion thread: http://www.marineengine.com/boat-forum/showthread.php?437661-Honda-BF225-Corrosion
- Found same oily/watery mixture left over in intake manifold cavity
- found lots of salt grains and particles in both intake and exhaust passages/pipes, and other areas
- No signs of water jacket / block corrosion like others, including in V between cylinders which seems common
- Some plugs (3 of 6) showing rust, others not looking great, will be replaced
Once I got the cylinder heads off and took a look at cylinders/pistons it seems clear that some water got into the cylinder head area for sure, and a bit into tops of cylinders. #6 was worst and showed a oily/watery mix left over. However, the cylinders themselves look pretty good - no signs of major rust, just light surface rust (no texture to it) and mostly near the top of the cylinders. Mostly coming off with WD40 + scotchbrite pad. I don't have any experience looking at the inside of motors but from what I've read I don't think a major hone or machine shop job is needed on the cylinders. Same with pistons, carbon/oil deposits but no major rust.
Water and rust definitely present around the valves though. Top of head (cam area) looks good with no signs of rust/water. Lower part of head (exhaust/inlet passages) definitely showing rust on valve stems and some rust particles/grains on top of valves, plus carbon/oil/light rust mixture on cylinder head walls + valves. I will be cleaning these up as much as I can without disassembling heads/valves to start.
I did find salt crud build up under the head gasket, between cylinders and water jacket passages, maybe a mm or so of buildup, present between pretty much all cylinders. I wonder if this could have allowed water into oil / cylinder area?
So wondering what caused this! And what next steps should be. It seems obvious that water made its way into cylinders from somewhere, I guess the options are intake, exhaust siphon (SB 56 - which this motor has not been upgraded for), cylinder head gasket failure, or water jacket failure. Based on the state of the internals of engine + accessory components, etc, I think it's unlikely to be a water jacket corrosion failure, but can't rule it out. SB56 / exhaust siphon could definitely have caused this I would think but from reading that bulletin it seems it doesn't usually affect all or multiple cylinders? Or possibly somehow it got in through intake side but I'm wondering how it ran so long without an issue and why it stopped working now. I never swamped the motor myself. In terms of head gasket failure, I don't see any obvious failure points but as mentioned above I wonder if crud buildup between block and gasket could have let water into cylinder area.
In terms of next steps, I see my options as:
- Clean up valves/heads/pistons/cylinders as much as possible myself, clean up old gasket, put heads back on and test compression/leak down to see if I'm going in the right direction
- Disassemble heads myself (a bit scared of this but I have the tools) and do a DIY cleaning of valves
- Send heads to machine shop (big delay as they are backed up for weeks/months, plus $$$) for valve job
I have all the parts (new gaskets, etc) and tools (valve spring clamp, shop crane) necessary to do whatever to engine but it is my first time taking an engine down this far. Hoping someone can point me in the right direction.
Thanks! Alex
Pics - milkly drained oil; #6 cylinder when first disassembled; #4-6 cylinders after some cleaning; valves from #1-3 head (can see salt crud build up in some)
View attachment 29089View attachment 29090View attachment 29091View attachment 29092View attachment 29093View attachment 29094
Engine/boat (21' Trophy) are new to me this year. Previous owner claims light use, only about 400 hours on motor, although I did not verify this (yeah yeah I know...). Judging by state of motor, how it looks internally, etc, seems to back up low hours.
I had used the motor for maybe 20-30 hours this year before going on an overnight trip where it died and would not start. Did not notice any issues up until this point, it maybe did not start right away on first spark but it started every key turn. On this trip we made it to the dock and then I went to move the boat to a new spot the next morning and it would not start - seemingly turning over but not catching. Went through everything I could at the dock, and fairly confidently eliminated any electrical issue up to the plugs - lots of juice in the batteries. No MIL / buzzer codes. Seemed to be a fuel issue so I thought maybe fuel pump and we had to be towed out of there.
Took it to a local Honda marine mechanic, wanting to get it quickly repaired and thinking it was something simple. Dumbly I had never actually compression / leak down tested it, but he proceeded to do that and found very poor results, plus rust on the plugs. Now pointing towards water getting into the cylinders. Compression results: #1: 140 psi; #2: 185 psi; #3: 150 psi; #4: 150 psi; #5: 180 psi; #6: 130 psi. Leak down loss results: #1: 70%; #2: 46%; #3: 38%; #4: 70%; #5: 50%; #6: 60%.
Pretty dismayed at this point with these terrible leak down results, he pointed towards pretty bad options financially from either scrapping the engine to cylinder boring, etc. From a financial standpoint I really couldn't afford to scrap this engine or pay someone huge cash to work on it so decided to go the DIY route and tear it down with an eye towards sending the heads or block to a machine shop, to keep things as cheap as possible while still recovering the engine.
So with shop manual in hand I began and have basically completed a tear down of engine to the point of getting the cylinder heads off (but block is still on the mount). What I found ...
- First big clue was the presence of what looks like significant amounts of water in the oil - the drained oil, the leftover oil in the pan, and the filter; milky/chocolate shake look, and very sludgy residue left in pan / filter - seems water definitely mixed with oil
- Also found what looks like white grease on the bottom of mount / top of oil pan - not sure if that's important
- Accessory components and shape overall of engine look pretty great - much better than what I've seen in some threads here, including passages/pipes, thermostats, block, manifolds, etc
- Very similar symptoms and clues as this Corrosion thread: http://www.marineengine.com/boat-forum/showthread.php?437661-Honda-BF225-Corrosion
- Found same oily/watery mixture left over in intake manifold cavity
- found lots of salt grains and particles in both intake and exhaust passages/pipes, and other areas
- No signs of water jacket / block corrosion like others, including in V between cylinders which seems common
- Some plugs (3 of 6) showing rust, others not looking great, will be replaced
Once I got the cylinder heads off and took a look at cylinders/pistons it seems clear that some water got into the cylinder head area for sure, and a bit into tops of cylinders. #6 was worst and showed a oily/watery mix left over. However, the cylinders themselves look pretty good - no signs of major rust, just light surface rust (no texture to it) and mostly near the top of the cylinders. Mostly coming off with WD40 + scotchbrite pad. I don't have any experience looking at the inside of motors but from what I've read I don't think a major hone or machine shop job is needed on the cylinders. Same with pistons, carbon/oil deposits but no major rust.
Water and rust definitely present around the valves though. Top of head (cam area) looks good with no signs of rust/water. Lower part of head (exhaust/inlet passages) definitely showing rust on valve stems and some rust particles/grains on top of valves, plus carbon/oil/light rust mixture on cylinder head walls + valves. I will be cleaning these up as much as I can without disassembling heads/valves to start.
I did find salt crud build up under the head gasket, between cylinders and water jacket passages, maybe a mm or so of buildup, present between pretty much all cylinders. I wonder if this could have allowed water into oil / cylinder area?
So wondering what caused this! And what next steps should be. It seems obvious that water made its way into cylinders from somewhere, I guess the options are intake, exhaust siphon (SB 56 - which this motor has not been upgraded for), cylinder head gasket failure, or water jacket failure. Based on the state of the internals of engine + accessory components, etc, I think it's unlikely to be a water jacket corrosion failure, but can't rule it out. SB56 / exhaust siphon could definitely have caused this I would think but from reading that bulletin it seems it doesn't usually affect all or multiple cylinders? Or possibly somehow it got in through intake side but I'm wondering how it ran so long without an issue and why it stopped working now. I never swamped the motor myself. In terms of head gasket failure, I don't see any obvious failure points but as mentioned above I wonder if crud buildup between block and gasket could have let water into cylinder area.
In terms of next steps, I see my options as:
- Clean up valves/heads/pistons/cylinders as much as possible myself, clean up old gasket, put heads back on and test compression/leak down to see if I'm going in the right direction
- Disassemble heads myself (a bit scared of this but I have the tools) and do a DIY cleaning of valves
- Send heads to machine shop (big delay as they are backed up for weeks/months, plus $$$) for valve job
I have all the parts (new gaskets, etc) and tools (valve spring clamp, shop crane) necessary to do whatever to engine but it is my first time taking an engine down this far. Hoping someone can point me in the right direction.
Thanks! Alex
Pics - milkly drained oil; #6 cylinder when first disassembled; #4-6 cylinders after some cleaning; valves from #1-3 head (can see salt crud build up in some)
View attachment 29089View attachment 29090View attachment 29091View attachment 29092View attachment 29093View attachment 29094