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2000 Honda 50 intermittent lack of power and oil leak

greyg8r

New member
Hello, newbie to this forum.

I have a 2000 Honda 50 BF50AY LRTA that I purchased a couple of months ago. When I purchased it, it had two obvious issues; an overheat issue and a running rough issue (it would only start and stay running with the manual choke on). I could not run the boat in open water until these issues were addressed.

I resolved the overheat issue by replacing the water pump (the vanes were totally disintegrated) and removing the head and cleaning out a lot of scale that was blocking flow.

I cleaned the carbs and the main jet on all three carbs was clogged. I replaced these and the engine idled great in the tank.

I took the boat out and it idled great in the no wake zone, but once I started to accelerate, it bogged down and stalled out. I had to restart it seveal times, each time using the fast idle / choke lever. Eventually I was able to get it going and after a few efforts, got it up to full throttle. This process was repeated the next 5 or so times I took the boat out.

This sure seems like a fuel delivery issue. The fuel filter inside the engine seems to flow without resistance. The bulb is between the Racor water separator/filter and the engine. It primes the carbs and stays hard. The Racor fuel filter is new. The fuel is new. The vent on the fuel tank is open.

Then, today, it ran great! No hesitation whatsoever. I did not do anything to warrant this. Any explanations why it works now?

I have ordered a Carbtune Pro to sync the carbs and hope that will help in the future.

Second issue: oil leak.

Oil leaks out of the foot. It doesn't leak when not running, but leaks when running and after turning it off. I did an oil change after cleaning out the scale. I don't see any leaks under the oil filter or below the valve cover. How can I tell if it is leaking from the lower seal around the crankshaft?

Any help would be appreciated.
 
Just a thought....your carbs may not have been completely cleaned, but managed to clean themselves. Sometimes, just using the choke when the engine is running up can help the engine suck some of the debris that is plugging the carburetors on though.

That is not a very common fix, but every once it a while it can work.....maybe that is what happened.

It will be good to balance the carbs when you get your gauges.

As for the oil leak. I assume that you are sure that it is motor oil. You can smell the difference between gear lube and motor oil.

Since you had the head off, that is the first thing that I would question. Questions like, did you use a new and correct gasket? Torque the bolts correctly? Clean the surfaces properly before reassemble? I think you get the idea.

Also, could it be possible that you put too much oil in the motor? The oil level should be about 1/4 inch below the full mark. If it is over the mark, then the excess could be finding its way out.

The only way that I know to see if there is a leak at the lower crank seal is to remove the powerhead and look.

Mike
 
Thanks, Mike, I was hoping you would chime in.

First, if the carbs cleaned themselves, sweet! I'll continue to monitor this. I received my Carbtune Pro today and will take a look at syncing the carbs before I take the boat out again.

Second, the engine is definitely losing motor oil as I have to add it. The oil does not leak when the engine is cold, but leaks out of the hole (circled in picture) in the lower unit while the engine is running and for a time after the engine is turned off while the engine is still warm. The boat leaves a visible sheen on the water.

I think I installed the head gasket correctly. From memory of my days as a certified auto mechanic 3 decades ago, the only way oil could be lost out of the water circulation would be if there was a breach between the cylinder and water jacket, but I think that would result in the compression being compromised. The compression after replacing the head gasket was 185, 185 and 180 (although I think these may be low as my compression tester occasionally leaks). There is no evidence of oil leaking below the oil filter or the cylinder head cover.

Does oil leaking out of the lower unit suggest the origin of the oil leak?
 
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The oil can leak into the water passage at the top of the cylinder block. Is part #6 installed with a new o ring? If the head surface is uneven, the oil passage is right next to the water passage. http://www.boats.net/parts/search/Honda/Outboard Engine/2000/BF50AY LRTA/CYLINDER BLOCK/parts.html

There may also be issues with the oil pump or the oil return line.

You could remove your lower unit after the motor has been run and see if the oil is coming down the water tube, exhaust, or other areas.

Unfortunately, oil leaks are a pain to find. If you didn't have problems before you did the head work, then the first place I would look is anything you did related to the head. If it was there before, you just have to start tracing the oil back to the source.....like peeling an onion.
 
The oil can leak into the water passage at the top of the cylinder block. Is part #6 installed with a new o ring? If the head surface is uneven, the oil passage is right next to the water passage. http://www.boats.net/parts/search/Honda/Outboard Engine/2000/BF50AY LRTA/CYLINDER BLOCK/parts.html

I don't recall replacing part #6 when I replaced the head gasket. Is it under the head cover? I don't recall receiving it when I purchased the head gasket.

There may also be issues with the oil pump or the oil return line.

You could remove your lower unit after the motor has been run and see if the oil is coming down the water tube, exhaust, or other areas.

Unfortunately, oil leaks are a pain to find. If you didn't have problems before you did the head work, then the first place I would look is anything you did related to the head. If it was there before, you just have to start tracing the oil back to the source.....like peeling an onion.

Unfortunately, the engine was overheating and running poorly when I purchased it and wasn't able to run it for long. That said, I don't recall any oil leaking at first.

honda50lowerunit.jpg
What comes out of the circled hole? That is where I will start tracing the leak because that is where the oil is definitely coming out of. I don't know about the exhaust.

Thanks again, Mike

Richard
 
Part 6 is in the block. The manual says to replace its o ring. It might be perfectly fine. Unfortunately, you have to remove the head to get to it.

I think the lower hole is an exhaust relief.....not really sure.

I agree....that is a good place to start

Mike
 
Sorry for taking so long, but I wanted to be sure of the facts, but I have an update:

First, I noticed water in the oil shortly after these posts.
Second, I pulled the head and noticed pitting on the head that I had not noticed before.
Third, after having the head milled, I re-installed the head and the oil leak is gone - there is no oil film on the water surface and I do not have to add oil - and the water leak is apparently is gone because the oil is not milky.

I could not find part no. 6, so I didn't do anything with

So, the leak issue was apparently from the pitted head and is fixed.

But, the second problem - losing power when hot - continues. I did notice a few things today when I took it out:

The engine starts great with choke on and fast idle lever up. After about 30 seconds, I put the fast idle lever down and push in the choke and it will idle forever. But, once warm and in gear, the engine loses power and nearly stalls out. I checked the primer bulb, but it stays hard, so I don't think that is the problem. If I manually keep the choke out, the engine runs great!

So, the engine seems to run lean once warm, but not when cold.

Questions: If it were the carbs, wouldn't they run too lean at idle also?
Can the carbs be adjusted even though they have limiters on the screws?
Would syncing the carbs help? I have a carbtune kit but haven't synced the carbs yet.

Any ideas?

Thanks in advance. Richard
 
Update: I cleaned the carbs (found brown crusty stuff in bowl), replaced the air mixture screws, pre-set them to 1 screw turn out but got better performance with 2 screw turns out, changed the gas, and drained the Rancor. Idles better than ever now. At first, even when the engine seemed to run okay, when I pulled the top cylinder plug wire, the engine did not noticeably falter (it ran poorly when I pulled the middle wire and stalled out when I pulled the bottom wire). Now when I pull each wire, the engine runs equally poorly.

So, here's a list of what was wrong:
Water pump impeller was completely broken
Head was blocked with corrosion
All three carbs were dirty
Head was pitted and allowed water into the oil and oil into the water
 
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