1989 30 hp elf lower unit

[JRM80000]

I have a 1989 30 elf that has developed a crack in the lower unit housing adjacent to the water pump. It is leaking oil and it will be necessary to replace the lower unit housing or the entire lower unit. I ran across a post in this forum from someone else that was looking for a complete lower unit, and found like me, that lower units for this model are few and far between. He was advised by the super moderater that a lower unit from a 1997-2000 25 hp Yamaha would fit his 30 hp Yamaha. If that is true, lower units for a 25 hp are much easier to find than one for a 30 hp and that will make my search more expansive. In fact, I have found one but it is from a 1994, not a 1997. The 1994 has the same part number as a 1997 and it seems as though it will fit my engine. Both the 1997 and 1994 25 hp have the same part number (6l2-45311-02-4d), so I should be good to go. The only difference I can see from the parts diagram is that the lower unit from the 25 hp has an end cap rather than the big nut holding the rear bearing in place. That being the case, it may require a prop for a 25 hp, but I'm not sure.

Can anyone tell me if the 25 hp lower unit will bolt on to my 30 ELF?

Thank you,

Jim McCarthy

[boscoe99]

Shift shaft configuration is different on the 25 and 30 HP models. Casing is different.

I am guessing that a 25 gear case won't work on a 30.

[boscoe99]

[Yamaha Rocks]

I have the same exact motor with same problem...can’t find a lower unit anywhere... heard a 40hp and/or a 50 hp lower unit will work anyone know if this is true?....are the aftermarket casings junk?

[Yamaha Rocks]

JRM80000 what did you end up doing?

[JRM80000]

I'm sorry to tell you that i haven't found a solution yet. I think the ultimate is going to be a new engine. As far as i can tell, the lower unit on the 30 hp is unique and no other lower unit will fit. I may take my lower unit to the machine shop to see if they can save it, but i'm not optimistic. It's really disappointing because this has been one of the most dependable outboards i've ever owned. I put the key in it and it goes, every time.

I looked into the chinese lower unit housings, but was not comfortable that they knew what they had. Because this lower unit housing seems to be so unique, i backed away from the aftermarket housing. As far as the housings from a 40 or 50 hp, i spent hours crossreferencing them until i was satisfied that they would not fit. As far as the 25 hp lower unit is concerned, i called the parts people at boats.net and they could not verify that a 25 hp unit would work. I also spoke to the local dealer and got the same answer.

I have run across a couple of lower units for the 30 hp, but too late both times. They were both sold bu the time i got there. In the meantime, i've recommissioned another boat i have and will just keep looking for either another lower unit or a suitable replacement engine.

Sorry i don't have better news for you.

[Yamaha Rocks]

Hey JRM8000 I end up taking my motor to a local guy that tug welds and he welded my lower unit crack up last weekend... looks pretty darn good I was surprised! I still need to have the lower unit looked at as I”m sure I ruined some seals and maybe a reverse gear... I can try and post some pics but not very good at that!...

[Yamaha Rocks]

That’s tig weld

[JRM80000]

Where was your crack? Mine is right along side the water pump so I was doubtful it could be welded. If you can post a photo that might be helpful. If your crack is in the same area as mine, I'm headed for the nearest machine shop.

Thanks for letting me know how yours turned out.

[Yamaha Rocks]

[Yamaha Rocks]

[Yamaha Rocks]

Crack on mine was r shaped.. if you look hard you can see it

[JRM80000]

Thanks for the photo. My crack is quite a bit more complicated as it is internal. You got lucky with a good fix. I don't think i'll be as lucky. My search goes on.