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Honda 5HP (BF5A) Leaking Oil When Tilted

J

jackshirkflyfishing

New member
Hi everyone, I have a pretty new (bought last summer) Honda 5 HP. I have used it quite a bit over the last year but just recently noticed that after transport, when I put it on my drift boat and tilt it up, oil has begun leaking out of the case. I am having trouble locating where it is coming from but it seems to only leak a small amount and then it stops and wont leak again rest of the day.

It is not a ton of oil and only seems to do it after or during transport. It seems to be running fine, and the oil light has stayed green. The first time I saw it leaking, I added some oil to it just to be safe but now it has done it the last 3 trips to the river and seems to be leaking more the last time.

Has anyone had this type of issue before? The motor has been well kept and ran frequently. Plus its less than a year old. Thanks in advance for any advice. I've worked on cars my whole life but never on an outboard. Hoping to take this on myself as my local marine is out about 5-6 weeks right now. If more details are needed just let me know can add pictures as well if that would help. Thanks!
 
When you say "transport", do you mean laying it on it's side?

If so, I would suspect that some oil is getting sloshed into the crankcase vent system during travel.

I don't know the 5 hp well at all but most of the small displacement engines do just fine running with the oil level lower than the full mark. If your dipstick has a "full" and "add" line, try keeping your oil level between the two in the "safe" zone and see if that helps with this. Refererence items 2, 3, 4, 5, 8, 15 and 16 in the parts page link below.

Honda Outboard 5HP OEM Parts Diagram for Cylinder | Boats.net

Buy OEM Parts for Honda Outboard 5HP Cylinder Diagram
www.boats.net www.boats.net

Good luck.
 
jgmo said:
When you say "transport", do you mean laying it on it's side?

If so, I would suspect that some oil is getting sloshed into the crankcase vent system during travel.

I don't know the 5 hp well at all but most of the small displacement engines do just fine running with the oil level lower than the full mark. If your dipstick has a "full" and "add" line, try keeping your oil level between the two in the "safe" zone and see if that helps with this. Refererence items 2, 3, 4, 5, 8, 15 and 16 in the parts page link below.

Honda Outboard 5HP OEM Parts Diagram for Cylinder | Boats.net

Buy OEM Parts for Honda Outboard 5HP Cylinder Diagram
www.boats.net www.boats.net

Good luck.
Click to expand...
Yessir, I pull it off the boat and lay it on its side. The first time it did it was after a 12 hour drive so that sounds like a solid idea. Okay will do regarding the oil level and reference items. Thank you for your advice!
 
You might note that item #2 isn't listed in the description and price list so that might mean that it's no longer available as a supported replacement part. Honda (as well as most manufacturers these days) discontinues supplying parts much too soon in my opinion. I think item 2 is some sort of cleanable screen but I don't know for sure.

The vent is only designed to handle crankcase vapors and send them to the engine air intake for re-burn. So, if liquid has been getting in there it might be best to go in and dry things out. That maintenance could also involve replacing filter A and filter B (items 15 and 16) as well as draining the vent hose, item 8.

I don't know how accessible all that is but, hopefully, it's not a total beast of a chore.

Good luck.
 
Any issue with which side you lay this outboard down on, a neighbour had a problem with a Yamaha and another with a Merc. The Manual said which side to lay the 4 strokes down on, my Honda mower could only be laid over 1 way to clean it.
 
Hey all, thanks for the input - Yes it can only be stored/transported on one side which they have marked and I have always followed.

With that said, I went out to the garage last night and it appears that is has leaked all it oil. I store it on a flat surface on some cardboard to prevent it getting scratched and the entire cardboard piece is saturated with oil. Not sure if that helps at all but definitely what started as a small leak appears to have turned into something major. Planning to try and work on it tonight, ill keep you all posted. thank you for the help
 
jgmo said:
You might note that item #2 isn't listed in the description and price list so that might mean that it's no longer available as a supported replacement part. Honda (as well as most manufacturers these days) discontinues supplying parts much too soon in my opinion. I think item 2 is some sort of cleanable screen but I don't know for sure.

The vent is only designed to handle crankcase vapors and send them to the engine air intake for re-burn. So, if liquid has been getting in there it might be best to go in and dry things out. That maintenance could also involve replacing filter A and filter B (items 15 and 16) as well as draining the vent hose, item 8.

I don't know how accessible all that is but, hopefully, it's not a total beast of a chore.

Good luck.
Click to expand...
Hey jgmo, I took at look at all the items and everything seems to be in order - I did notice on the carb there is maybe a missing hose? Take a look at the pic and let me know what you think

IMG_4136.jpg
 
I believe that's the carburetor drain spout. And, yes, there should probably be a clear vinyl hose attached there. See item 25 in the link below.

Honda Outboard 5HP OEM Parts Diagram for CARBURETOR | Boats.net

Buy OEM Parts for Honda Outboard 5HP CARBURETOR Diagram
www.boats.net www.boats.net

That hose then connects to a drain to the outside of the lower, horizontal portion of the engine cover. The drain location is notated by the number 14 in the link below.

Honda Outboard 5HP OEM Parts Diagram for ENGINE COVER | Boats.net

Buy OEM Parts for Honda Outboard 5HP ENGINE COVER Diagram
www.boats.net www.boats.net

I hope you find where the oil is coming from. It may be from under the flywheel if the upper crankshaft seal has failed in some way. But, that's just a guess.

Good luck
 
Should have said the receptacle for the carb drain hose is noted by E 14 in the parts illustration.
Sorry if that caused confusion.
 
jsyangyu said:
I bought March 2021, similar issue. Oil leaks after transportation on the side. The leg side rubber seal got deformed by oil.
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attached pictures there, the oil leak issue is very annoying. I read some posts saying 4 stroke engine no suppose transport in laydown position for long.
 

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I am experiencing the same oil leak problem on my nearly new 5 HP Honda outboard. On the first visit the dealer said that I had tilted the motor head more than 30 degrees back towards the rear of the motor. I had been very careful to transport and store the motor on the designated side, per the manual. I accepted the dealer’s explanation, paid $200 to have the oil mopped out and spark plug replaced (fouled with motor oil). The tech loaded it carefully into my pickup.

By the time I arrived home — 30 miles on paved roads — the oil had again begun leaking. Over 24 hours, what appears to be all of the oil leaked out. It’s back in the shop and the dealer professes not to have ever seen such a problem.

There must be something wrong here, as no outboard could possibly have been designed in such a way that briefly tilting it in the rearward direction causes a major problem.

Sign me “Frustrated in Oregon.”
 
Hi,

I would be frustrated too. Although, I found out long ago that many 4 strokes are going leak oil if transported lying down. No matter what the manufacturer promises.

Could I ask you though, what model (A or D) do you have?

I ask because I see that the crankcase breather systems are slightly different between the two and I think that's where the oil is draining from.
 
Thanks for taking the time to read and reply to my post.

The motor is at the dealer for repair. So I'm not sure whether I have the A or D model.

I'm beginning to fear that I have the TUV ("temperamental, unreliable, delicate") model!
 
Well, no matter how you describe it, the 5 hp has always been my least favorite of all the Hondas I've been exposed to.
We had about 20 of them that we rented with boats on small lakes in the mid to late 2000s and they were a bit of a headache. They ran great but had some annoying issues. I always chalked it up to the abuse they took from customers.

It's been a minute and my memory isn't great but I do think that outboard was the one that forced us to build a large rack that we could secure on a trailer to transport them upright because of the oil leakage. There were usually a few each week that needed to come to our shop for repairs the docklands couldn't handle.
Pull starter breakage was common.

I will be interested in seeing what your dealer comes up with on this go round. Please keep us updated.

Good luck.
 
Interesting. I have a 2022 Honda BF5A. I stored it in the basement of the cabin. When about to change the oil at the end of the year, lots of oil went out. I thought it could have been the position it laid in on a plastic sled. Cabin on a river, and it pulls a Jon boat, the water pump went out, and the pull rope had a manufacturing defect. Dealer insisted user error but Honda came through with repairs at no charge. It runs good now, but I always store it on the boat or in a stand upright. It will still leak oil when transporting on its designated side.
 
Hi riverfishing,

Welcome to the Forum!

Thanks for sharing your experience with the Honda 5hp.

It would appear that not much has changed since I was "put off" by issues with that model.

I will say though, in it's defense, that it is an excellent running outboard and that MANY 4 strokes....most in my experience...will eventually leak oil if stored laying down.

Your troubles illustrate that there's probably some improvements needed for that model to make it a better choice for buyers.

Your decision to store upright is a good one. That or completely draining the sump is the best way to store or transport that model for sure.

I also appreciate your relating as to the GREAT treatment you received from Honda Marine in spite of how their dealer wanted to brush you off.

Honda is a great manufacturer producing some of the best ever outboard motors ever made. I have one (20hp) and have always loved it.

But, as with almost anything we might discuss, there's always room for some needed improvement.

Cheers and stay safe out there!
 
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