Oil leaking from propeller

ATPNW

Member
Went to do the winterization of the 2005 Honda bf50’s today (four strokes). Before starting, I noticed an oil stain below the starboard motor. It smells like motor oil, not like gear oil. After using this motor last, I noticed the oil was very low. So I’m assuming there is a leak. Any suggestions on where to start looking?
 
Did you spill any when you last changed it? I find that when changing the filter it is very difficult not to spill some oil. This runs down the inside of the motor casing and collects at the bottom. Only way to really clean it up is to take the casing off. You can see the oil sheen when the motor is in the water.

But since you said the oil level was also low, perhaps the filter is not tight.

I had a problem with my motor losing oil awhile ago. It turned out that I did not tighten one of the rocker cover bolts after checking the valve clearance.
 
ATPNW,
If it is engine oil, vice lower unit oil, the most likely issue is that the oil seals in the base of the oil pan (below the engine block) is leaking.
You may already know that the lower unit (gear) oil, usually has an odd smell, where the (used) engine oil will have a slight carbon/fuel smell.
 
I once had a worry that my nearly new engine was leaking oil when I saw a small puddle of oil below the propellers. Turned out I had slightly overfilled when I changed the oil.
 
Hi All,

Long delay but life got busy there for a moment. Took the lower unit off today and sure enough there is a oil leak coming from that tube in the photo (assuming that is the exhaust)? I took the midsection "skirt" off to see if there was any external oil leak, but couldnt find any. So im pretty sure its internal. Since the oil was very low last time I changed the oil, im wondering if this would be blow by?

SRBaum mentioned oil seals at the base of the pan, from my understanding I'd be taking the power head off to get to that, correct?

I guess i could also do a leak down/compression test but those if positive will point to tearing the engine apart. I guess I am wondering if there is any other quick things to check before going down that road?

The motors are 2005's, and im sorta starting to wonder if now is the time to bite the bullet and repower.


Image below is witht the lower unit off, you are looking up into the mid section.
IMG_0492.jpg
 
srbaum":32grd1ws said:
ATPNW,
All of the failures that I have seen, that are as you described have been the seals at the base of the crankshaft. See parts number 7 & 8 on the attachment.
https://www.boats.net/catalog/honda/out ... -gear-case
PS, just had two outboards with the same issues over the last several months. I work on small outboards for a hobby and have messed with over 250 to date...

Thank you Steve for the link and lending your expertise! With the parts being less than $20, it seems like I should explore this a bit more. A couple questions for you if I may:

1. There is no way to change those seals without removing the powerhead, correct? Anything else I should be inspecting or replacing with the powerhead off?

2. The oil level on the dipstick hasn’t changed since I did the oil change a few months ago (the boat has also not been run since then). Would that further confirm your suspicions? It only leaks when the crankshaft is running?

Thank you!
 
ATPNW,
It would be great if you would say what your name is... Otherwise, I feel like I am only talking to a machine.
As to your oil leak:

1. Take a sample of oil from your dipstick and a sample of oil from the stuff dripping out of the lower unit. Touch it and smell it to ensure that it is the same oil. Lower unit 90W gear oil has a completely different odor and color.
2. When I replace crankcase seals, I disassemble the entire engine (powerhead). Each part is cleaned, inspected and measured to ensure that it still meets manufacturers specifications. If a part can't meet spec, then it is replaced.
3. Assembly includes replacing of all parts not within spec, parts that show excessive corrosion, all new seals, gaskets, filters, oil, lubricant. The repairs also include the same inspection and service to the mid section and the lower unit.

So, a quick repair can't be anticipated and the expense will certainly be in the hundred of dollars (for all parts not including labor). This is the way that I do it and i'm careful to ensure that the outboard will perform as new, to ensure reliability as well as confidence.

Best regards,
Steve Baum
 
srbaum":1yin55k5 said:
ATPNW,
It would be great if you would say what your name is... Otherwise, I feel like I am only talking to a machine.
As to your oil leak:

1. Take a sample of oil from your dipstick and a sample of oil from the stuff dripping out of the lower unit. Touch it and smell it to ensure that it is the same oil. Lower unit 90W gear oil has a completely different odor and color.
2. When I replace crankcase seals, I disassemble the entire engine (powerhead). Each part is cleaned, inspected and measured to ensure that it still meets manufacturers specifications. If a part can't meet spec, then it is replaced.
3. Assembly includes replacing of all parts not within spec, parts that show excessive corrosion, all new seals, gaskets, filters, oil, lubricant. The repairs also include the same inspection and service to the mid section and the lower unit.

So, a quick repair can't be anticipated and the expense will certainly be in the hundred of dollars (for all parts not including labor). This is the way that I do it and i'm careful to ensure that the outboard will perform as new, to ensure reliability as well as confidence.

Best regards,
Steve Baum

My apologies, I thought my name was in the sidebar. My name is Alex. I appreciate your elaboration on the process. Haven’t 100% decided to go for the fix or repower yet. But if I go for the fix I’ll be sure to document it all here.

Best,
 
Alex,

Just wondering how much oil the engine is leaking? Maybe the next time out make sure it's full and then when you return check the dipstick. I know you said the level was very low on your original post, how much had you run the motor before you had checked?

If the motor is not using/leaking a lot of oil, it may be fine to just add when needed until you either replace seals or repower.

Patrick
 
Alex,
Thanks for stating your name…
I wished you were closer to me, as a teach people how to maintain and perform major service to their outboards….
Best regards,
Steve Baum
 
Salmon Fisher":12gy1wso said:
Alex,

Just wondering how much oil the engine is leaking? Maybe the next time out make sure it's full and then when you return check the dipstick. I know you said the level was very low on your original post, how much had you run the motor before you had checked?

If the motor is not using/leaking a lot of oil, it may be fine to just add when needed until you either replace seals or repower.

Patrick

You know that is a good point. When I noticed the leak was when we got back from a 5 day trip from the coast. The boat was moored every night, so didn’t get an opportunity to see how much was being used each day. After getting home is when I checked the oil level and noticed the problem. We probably put 25-30hrs on it during those 5 days.
 
srbaum":391rhk86 said:
Alex,
Thanks for stating your name…
I wished you were closer to me, as a teach people how to maintain and perform major service to their outboards….
Best regards,
Steve Baum

I really appreciate the offer, wish I lived closer to take you up on that. I have enjoyed getting to work on and maintain the engines.
 
Salmon Fisher":jzhtpf8g said:
Alex,

Just wondering how much oil the engine is leaking? Maybe the next time out make sure it's full and then when you return check the dipstick. I know you said the level was very low on your original post, how much had you run the motor before you had checked?

If the motor is not using/leaking a lot of oil, it may be fine to just add when needed until you either replace seals or repower.

Patrick

Agreed. Or switch from synthetic back to regular old oil. I'd probably even experiment with viscosities before I tore it apart. If it's just a seep, it sometimes doesn't take much to get it to quit or be livable. With that said, tearing an engine down isn't the end of the world....it just takes time, parts, patience, lots of money, and tools....lol...Speaking of which....I just put a motor back together because it sprung a leak. Never ends.....
 
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