Water in the lower unit of a Yamaha 6a1 2hp outboard

[merjan]

I was fixing the kill switch of an old 2hp 2-stroke Yamaha outboard (6a1), and "while I was at it" I cleaned the waterways, and replaced the impeller and the seals of the lower unit... and ended up with water leaks into the lower unit. This is how new oil looks like after running the engine for 5 minutes



Now I'd like to figure out whether the amount of "froth" in the oil is acceptable, and if not, to figure out how to rank the potential culprits. So firstly, looking at the picture, would anyone say whether I definitely need to fix this or that's fine"?

As for how I installed the new seals, looking at this diagram
Yamaha Outboard Parts - 2 MHS 2B (6A1) / Europe (030) / 1999 - Lower Casing & Drive 1
I put two seals above the impeller housing and one below under the bowl where the impeler sits. There are two types of seals, one type is slightly slimmer than the other. It wasn't clear in the diagram which one goes where. Judging by what I removed, I put the two slim ones above the impeller housing, and the one thicker one below it. In both cases "lips" have been facing towards me as I tap them into place, ie the flat sides of the seals away from me. Does that sound right to anyone who remembers how these go?

I would be very grateful for any advice!

 

[VicS]

Its not the froth that is important it is the ingress of water that is not acceptable.

The critical seals which you will have to re-examine are the prop shaft seal ( #16), the O ring (#17),the drive shaft seal (#7) and the drain and level plug seals (#9).

The parts diagram shows the correct orientation of the spring seals
.
The level plug screw in your picture does not look right ( presumably the drain screw is the same) They normally fit with the head flush with the outside of the gear casing and look like this with a flat sealing washer (#9) under the head, but it is along time since I last had anything to do with a small Yamaha

 

[merjan]

Thank

Its not the froth that is important it is the ingress of water that is not acceptable.

The critical seals which you will have to re-examine are the prop shaft seal ( #16), the O ring (#17),the drive shaft seal (#7) and the drain and level plug seals (#9).

The parts diagram shows the correct orientation of the spring seals
.
The level plug screw in your picture does not look right ( presumably the drain screw is the same) They normally fit with the head flush with the outside of the gear casing and look like this with a flat sealing washer (#9) under the head, but it is along time since I last had anything to do with a small Yamaha

Thank you - the #9s are aftermarket ones are are now very tight.

I changed the #16 prop shaft seal again. The other aftermarket one was slightly different (and symmetric). When I ran the engine and drained the oil again, I couldn't tell if there was any water. Fingers crossed it is OK this time.

 

[VicS]

Thank

Thank you - the #9s are aftermarket ones are are now very tight.

I changed the #16 prop shaft seal again. The other aftermarket one was slightly different (and symmetric). When I ran the engine and drained the oil again, I couldn't tell if there was any water. Fingers crossed it is OK this time.

The oil will go milky if there is water present. While it remains "clear and bright" you know there is no water ingress