Honda BF90A Water in fuel - then stored...am I thinking right?

LoopZilla

Recruit
Joined
Jan 8, 2011
Messages
4
I am considering purchasing a RIB with a Honda BF90A, and am attempting to do due diligence before purchasing. The boat owner is a friend, so I have the boat for a while to decide. I know for a fact the owner swamped the boat, allowed water to enter the fuel tanks, and continued to run the boat until it quit. Engine was never in the water. The boat was then stored for over a year.

Steps I have taken:

1. I removed the spark plugs and couldn't see much through the plug holes. I shot the cylinders with SeaFoam Deep Creep and let it sit.
2. Drained engine oil to check for water, and there was none. Oil looked clean with no metal. Refilled to proper levels.
3. Checked lower foot oil, all good. Refilled.
4. Applied power to motor to check trim system. All good. And checked and replaced fluids.
5. Checked power to electrical system, all good.
6. Removed intake manifold with carbs. They will obviously need rebuild, so skip fuel system for now.
7. Fogged intake valve ports with SeaFoam, and inspected. Slight corrosion on valve rods, but can't see the seats. Corrosion rubs off with rag after foaming.
8. Removed the valve cover and saw no evidence of corrosion or water. Bearings looked OK. Fogged and replaced cover.
9. Turned the motor over by hand, it feels ok and wasn't stuck - surprisingly. All intake valves look to be operating properly, but I can't see the valve seats.
10. Tried to turn over the engine via the starter motor to allow me to check compression, but found the starter motor didn't have enough torque to turn the engine. I believe the owner burned it up trying to get engine running again.
11. Removed the starter and disassembled. Brushes and commutator are within spec, but there is a short between the shaft and the armature (checked per service manual). Need a new rotor.

OK - here is the plan. I have to get the starter fixed at a cost of at least $300, just to get the engine turning enough to get a good compression test on each cylinder. I can't pull the string fast or consistently enough, but I am getting 'some' pressure on each cylinder. My thinking is that the compression test will tell me the condition of the rings, cylinders and valves. Am I thinking correctly, or is this engine going to need a valve job anyway?

Then, I wouldn't mind putting the cash and time into rebuilding the carbs - especially if I could find a rebuild kit (I can only find individual parts for Honda outboards online).

I haven't gotten to the cooling system yet, but the sacrificial anodes in the intake manifold look OK.

Any thoughts would be appreciated! And, I could use some parts purchasing advice (vendors, kit numbers, etc.)!
 

isaksp00

Petty Officer 1st Class
Joined
Jul 14, 2010
Messages
225
Re: Honda BF90A Water in fuel - then stored...am I thinking right?

Can't help you with advice, as you obviously already know more than I do on steps to take. However, for parts, I have been using boats.net for my Honda 8HP, and they have done a good job getting parts for this roughly 16 yr old engine (individual carb parts, impeller, fuel pump diaphragm, etc.). They (and other sites) have pretty good parts diagrams that show part numbers, as long as you can figure out what section to look in.
 

LoopZilla

Recruit
Joined
Jan 8, 2011
Messages
4
Re: Honda BF90A Water in fuel - then stored...am I thinking right?

Thanks for your reply!

I'll give boats.net a call or eMail to see if they have carb rebuild kits. I'd rather know I have all the required parts on my bench before I get started, even if I don't use them all!
 

scallop

Cadet
Joined
Sep 22, 2009
Messages
12
Re: Honda BF90A Water in fuel - then stored...am I thinking right?

I am considering purchasing a RIB with a Honda BF90A, and am attempting to do due diligence before purchasing. The boat owner is a friend, so I have the boat for a while to decide. I know for a fact the owner swamped the boat, allowed water to enter the fuel tanks, and continued to run the boat until it quit. Engine was never in the water. The boat was then stored for over a year.

Steps I have taken:

1. I removed the spark plugs and couldn't see much through the plug holes. I shot the cylinders with SeaFoam Deep Creep and let it sit.
2. Drained engine oil to check for water, and there was none. Oil looked clean with no metal. Refilled to proper levels.
3. Checked lower foot oil, all good. Refilled.
4. Applied power to motor to check trim system. All good. And checked and replaced fluids.
5. Checked power to electrical system, all good.
6. Removed intake manifold with carbs. They will obviously need rebuild, so skip fuel system for now.
7. Fogged intake valve ports with SeaFoam, and inspected. Slight corrosion on valve rods, but can't see the seats. Corrosion rubs off with rag after foaming.
8. Removed the valve cover and saw no evidence of corrosion or water. Bearings looked OK. Fogged and replaced cover.
9. Turned the motor over by hand, it feels ok and wasn't stuck - surprisingly. All intake valves look to be operating properly, but I can't see the valve seats.
10. Tried to turn over the engine via the starter motor to allow me to check compression, but found the starter motor didn't have enough torque to turn the engine. I believe the owner burned it up trying to get engine running again.
11. Removed the starter and disassembled. Brushes and commutator are within spec, but there is a short between the shaft and the armature (checked per service manual). Need a new rotor.

OK - here is the plan. I have to get the starter fixed at a cost of at least $300, just to get the engine turning enough to get a good compression test on each cylinder. I can't pull the string fast or consistently enough, but I am getting 'some' pressure on each cylinder. My thinking is that the compression test will tell me the condition of the rings, cylinders and valves. Am I thinking correctly, or is this engine going to need a valve job anyway?

Then, I wouldn't mind putting the cash and time into rebuilding the carbs - especially if I could find a rebuild kit (I can only find individual parts for Honda outboards online).

I haven't gotten to the cooling system yet, but the sacrificial anodes in the intake manifold look OK.

Any thoughts would be appreciated! And, I could use some parts purchasing advice (vendors, kit numbers, etc.)!

Cleaning the carbs is a must do. If it was a recent problem the only part you usually need is the intake to block gasket. Everything else can be reused, after sitting a year only teardown will tell. The 2" or so long very skinny nozzle tube in each carb is very hard to clean so you might want to just buy them if you don't want do to a repeat cleaning.Probably a 5 hour job???
 

iowafish

Cadet
Joined
Jun 22, 2009
Messages
15
Re: Honda BF90A Water in fuel - then stored...am I thinking right?

My local Honda Marine mechanic gets 65 dollars per carb to clean and sync carbs. Had it done last spring and my BF 75A runs like new. In the unlikely event that lots of water was pulled into the engine, it's probably OK. Get the starter fixed, clean the carbs, pull the tank to clean it and go boating.
 
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