2010 Optimax 150hp oil issue

[150optimax]

Hi,
I have a 2010 Optimax 150XL and I recently took the engine off of my boat to repair an issue on my transom. After reinstalling it the aux oil tank leaks out into the engine and fills the cylinders with oil. After first glance it looks like I may have hooked up the oil lines wrong and I have since changed them. I have ordered a new check valve that goes into the engine block as it may have malfunctioned. My question does any one have any experience as to what other things can cause the injection oil to suction back into the engine while it is off. Luckily I removed the spark plug before trying to start it and noticed that the bottom left cylinder was full of oil.

Since reinstalling the lines correct I have noticed small amounts of oil still coming out the exhaust by the prop but nothing like before I changed the lines.

Any insight would be great, I think that the small check valve may be the faulty piece but just want some other advice input etc as to what else could malfunction. The boat has under 200 hours on it.

Thanks Eric

[SilverFox579]

Welcome Eric, please take a moment to read the Announcement at top of forum and post the required info (engine serial number at minimum). I can't think of what may, or may not be causing the problem you're experiencing but someone here will help you soon. I'd lean toward the check valve, but since the engine was removed/reinstalled, and I assume that issue didn't exist previously, don't know how it could have gone bad while sitting on a stand.

[leonreno]

Does your boat have a remote oil fill? If so did you over fill it after motor was reinstalled? That could cause oil to work up to the check valve and back flow into motor. The check valve (I think) is built with a slow leak to release air pressure from remote tank when motor is turned off. So it would allow oil to flow backwards even if it’s functioning properly.

[150optimax]

Thanks for the replies. Sorry about the info It is a 150XL Optimax serial 1B747617 thought it was a 2010 but a 2009 model.

I did not fill the oil tank after reinstalling it, it was about half full and almost all the oil over a week period suctioned back into the engine and the ground. (I usually try to store the engine upright so everything drains out)

I got my new engine check valve and went to install it last night. When I pulled it out I tried blowing both ways through it and it was the same as the new one that I bought. I replaced it simply because it was out but I don't think that that was a problem. You are right about the letting small amounts of air come back through it while it was pretty good not allowing the air to come out both new and used let a small amount of air through it which makes sense to slowly release air pressure from the aux tank.

Thanks for the advice on the overfilling of the tank, I am curious if there is a check valve in the tank itself that maybe is not working properly. I haven't found a parts breakdown of the auxillary tank to see if there is one in there.

[JOE54]

no check valve there

[EuropeanAM]

If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info with each post. Thanks!