I saw this and thought it does have some good information value that biggest purpose for me to post it is to dismiss a lot of myths about some that accidently added an extra quart into their engine.

Why did I post this thread.....No you are not likely to aqua lock the engine contrary to so many reported on various forums.

Other than that it is a fun video to watch.

Here's What the Inside of Your Engine Looks Like When It's Overfilled With Oil (msn.com)

 

We recently experienced an engine overfill by the dealership. My son and his wife have jet skis with supercharged engines. After being serviced at the dealer he took his 10 hour new ski out to the river and it ran sluggishly, wouldn't reach redline. Took it back to the dealer and they immediately suggested to remove and test the SC for slippage of the clutch discs. Big labor bill looming/possible rebuild of SC. That didn't sound right to him so he brought it home and we began to diagnose it before getting a second opinion. I found the oil sump was overfilled by a couple of inches, so I siphoned the excess out and checked the spark plugs, which were heavily fouled. Replaced the plugs and took it to the river again. It ran like new and was as fast as ever. Problem solved.Then we checked the other jet ski. It too was way overfilled.



192.168.100.1 192.168.1.1

 

That is another good example of you ALWAYS check the oil capacity when someone other than yourself does the oil change or adding oil.

 

It's always good to do your diagnosis if something doesn't seem quite right after a service. Dealerships are busy, and mistakes can happen. You know your vehicles well. It was smart to get a second opinion before approving any major work.