The first time we used the boat this spring, we noticed that the drive reservoir overflowed after running it. I had a mechanic check it. Was found to have water getting in the outdrive so it was thought that this was creating the problem via pressure build up. After testing, a leak was found and the lower outdrive case was replaced. After test running the boat, the problem occurred again. The upper case was replaced and the drive pressure tested fine. Upon test running the boat, overflow problem occurred again, but no water found in drive and again pressure tested fine. Drive switched to other side (twins). Problem did not move to other side, so drive problem now being ruled out as causing the overflow on the reservoir bottle. We now believe outdrive did have an issue which has been solved, but we are baffled as to what is continuing to cause the overflow/pressure build up on the one side. If anyone has seen this sort of problem your feedback would be appreciated……

Check and see if the rubber washer is in the lid of your resevoir bottle. The system is designed to build pressure with runnung the boat. If you dont have the rubber washer in the lid it will over flow everytime.Also want to make sure the drive is filled correctly from the bottom to the top. Also make sure the little orange rubber flap is in the top of the lid also.

John

Thanks for the feedback. All those issues are fine. We are starting to believe it might be something in the gimbal assembly. Any thoughts or ideas?

I would replace the oil reservoir cap first. 99% of the time that is the cause. Hope you don't find out what the other 1% is.

That doesn't seem to be it.....We are at a loss....drive checks out fine, its not the cap, so what else can it be? You mentioned the other 1%....I hate to ask, but it is????? We are discussing pulling engine to check gimbal but I sure hate to do that.......They are saying that is very very unlikely.....Anyone have other ideas on this.....??? Thanks for the responses....

I just posted a few minutes ago with a similar question; I probably should have checked this thread first. I'm hoping that my water in the gearcase oil and reservoir overflowing problem is due to an improper washer on the drain plug. I currently have one of my drives being serviced to address another issue (side to side play) but may be related to oil incursion. I'm also worried that that the check valve from the reservoir to the drive may be admitting water into the oil. Who knows? that's the question - keep me posted , Jeff

Hey 30outlaw, I'm curious why you'd have to pull the engine to check the gimbal assembly. I think just dropping the leg will give you all the access that you need. Good luck