Yamaha 4 stroke 40hp with Water in Lower Unit

[scjakester]

I started spring cleaning on my 40hp 4 stroke Yamaha last night and when I drained the foot I found water in the gear oil. Dangit! I pulled the lower unit to replace the impeller and I think its coming in through the upper seal (the one directly beneath the water pump). When you rotate the shaft you can see it bubbling up. Is this something I can DIY by just popping them in and out or do I need some sort of specialized tools or equipment to do it?

-Jake
Lexington, SC

 

[scjakester]

Re: Yamaha 4 stroke 40hp with Water in Lower Unit

I found this on YouTube (it is a 3 part video) about how to DIY the seal replacement but it is for a larger motor than mine. If the principle is the same, it looks like a pretty brilliant way to do it without taking everything apart. Things on the Internet can be deceiving, it looks straight forward enough, but just wanted to get some direction.

http://www.youtube.com/watch?v=VZzwLU07v8U

 

[99yam40]

Re: Yamaha 4 stroke 40hp with Water in Lower Unit

Not sure if special tools are needed on that 4 stroke or what they would be but just like with any other motor you need to pick up the service manual for it if you plan on working on it yourself. I will tell you what tools are needed and all the steps and specs are.

Some seals need to be set in to the right depth, so need special tools or at least measure the old ones before removing