Mercruiser Alpha One Gen2 Sterndrive getting water in gear oil

[crepko]

Hey guys,
After rebuilding the top half of the engine in my Chapparal boat that I purchased in July, we were finally ready to take it out on the lake and test it this weekend. But after testing the new impeller we recently installed, we drained the gear oil after a 20 minute run using a big bin of water to test the impeller, and we found quite a bit of water in the gear oil.

I have a lot of experience working on car engines, but this is my first boat, and I have no experience working on sterndrives (other than the impeller change we did). At this point I am debating on whether or not I should just take it to a professional to have the sterndrive serviced and pressure tested, or is this something that an average backyard mechanic could tackle?

If I take it to a professional for service, what kind of costs might I expect reasonably? The boat has 250 hours on it and everything looks very clean and newish (engine and drive).

Boat: 2007 Chapparal
Engine 5.0 Mercruiser Carburated
Engine: OW613721
Transom: OW437012
Drive: OW841226

 

[Rick Stephens]

Typically you would drain all the oil out of the drive and pressure test it. You can easily build a simple pressure tester and find the leak. For the most part, this requires not much skill, some patience and a tool you made. There is at least one seal, the input shaft behind the yoke and u-joints, that require some special tools to replace. Still cheaper than taking it to a 'professional' even if you buy the couple special tools.

You can find some info on what your pressure should do in the Adults Only section. A couple pictures even of how others built them.... mines pretty weird since I use it for testing pressure cooker gauges as well.