New 1999 Nitro 700 LX owner.

[Jeff Sondak]

Hi recently purchased a new used 99 700 LX with a 115hp...I noticed oil dripping on back of boat a little bit. Checked motor and seems like its been doing it for some time as I see some discoloration on the back of boat well. As well inside motor casing on bottom. Seems to be coming from top of oil reservoir and the weird cap cover for the oil fill. Anyone else experience this or is this something else that needs fixing.



Jeff

 

[Bob G.]

It's also possible that the oil is coming out of the carbs when the motor is tilted up for a prolonged period of time.

 

[Chris Droke]

My 170 DC does that too. I agree with bobg on the carbs because my oil tank has been removed. I run my 90 old school by prefixing oil.

 

[Jeff Sondak]

I noticed a lot of the oil in the bottom of the engine well. Motor is usually tilted down when stored. I did drive it back from storage yesterday with the motor tilted. Kinda very annoying as fairly messy...

 

[Dan Smith2]

my 2008 90 hp. mercury does the same thing when the motor is trimmed up . I am pretty sure that in my case it is coming from the oil tank.(bad cap design)

it only happens if there is too much oil in the tank. If you fill up your oil tank when the motor is trimmed down it will leak out of the cap when you trim it up due to the angle of the motor

 

[mike daniels]

Try putting a metal hose clamp around the neck of the oil tank where the cap is. There is an O-ring in there that needs a little more squeeze.



Fixed my 1999 Merc 90 ELPTO.

 

[Jeff Sondak]

Finally weather gave a chance to check this problem again... I added the clamp as suggested but no good, took boat out and when trailering a lot of oil leaked again all inside bottom cowl and on back of transom... Not cool and looks like doing this for a while as back transom is discolored where oil leaks... Any ideas or better fixes?

 

[Scott Hammer TOXIC]

My guess would be a leaky cap on your oil reservoir on the motor or bulk tank.

 

[Tim Greifer]

Had it happen on my old 700lx as well. Some mentioned some sort of "float" may be bad. Took it in whie getting other things done and told them. No issues after that. Not sure what they did though.

 

[Dan J.]

You need to diagnose the leak. Is it static or active? (Does the oil level drop after filling, but before using or only after use?) From there you can narrow it much easier. It could be as simple as an earlier overfill that glugged down inside the cowling and leeches out time after time (very common), the mentioned float sticking in the carbs, all the way up to a ghost leak from a hose connection weeping under pressure only. Additionally as mentioned, your engine will dribble the leftover, unspent fuel mix out your carbs trimmed up after use. It's just the nature of the beast. Good luck and let us know.