Clean 2 stroke oil leak, where could it possibly come from?

[Guest_User]

2 stroke oil leaking. this is clean unburned oil leaking. where could it possibly come from???
I have been all over this boat from day one of ownership and replaced a bazillion items/parts.
I am premixing.
ALL hoses, line, clamps have been replaced. I have a minor drool of oil out the bottom of the tank which is evident by running down the split loom covering the hose and collecting under the Port engine. That is not the issue.

I have OIL all over the back of the Starboard engine where the ID tag is. it is leaking enough to wet the back of the air box, run down either side above the PTO fywheel area...
Under the stainless cover that holds the electrical tower in place is DRY, so the seal isn`t leaking.
I had first thought it was oil from the balancing shaft gear reservoir, but it is not...

I am not 100% familiar with these 787`s. are there any gaskets, joints, fittings, seals, case surface issues that are know for this?

when running the boat earlier this year, I did not push the boat due to repairing and fixing ongoing issues. Now that everything had been addressed and now running at max rpm`s, the last 2 rides were running a bit harder and between 6-7K rpm`s which is what the boat was designed for... this is when I noticed the presence of a lot of oil on the starboard engine. under the engine is damp, but not soaking wet like the back. the hoses to the RV are secure and not dripping oil. there is a new stainless clamp along with a safety zip tie securing the new 1/2 ID tygon hoses.
I didn`t think there was any pressure in those hoses anyway that supply oil from the tank to the RV shaft/bearing.
so what can I look for or check? what could possibly be leaking that amount of oil to create a mess that runs down in to the bilge?

at least it is the end of the season for us, and the boat is being disassembled for winter storage. I already have the drive line/pumps and various parts on the shelves in the garage.

I plan on pulling the engines and storing them indoors.

I hope to find where this leak is before my reman warranty expires... Thanks.

 

[Albysure]

Pale did u find leak?.... I have the 717 engines and after running it today for a little I noticed a small oil leak from the right motor...when I got home I cleaned it up...let it sit the rest of day and I just went out there to check and no oil....so I hooked up hose and started it and let it run for a min....the oil started to leak...I got upside down and my gasket on my premix was leaking......not sure if u have premix still or not.

 

[Guest_User]

Pale did u find leak?.... I have the 717 engines and after running it today for a little I noticed a small oil leak from the right motor...when I got home I cleaned it up...let it sit the rest of day and I just went out there to check and no oil....so I hooked up hose and started it and let it run for a min....the oil started to leak...I got upside down and my gasket on my premix was leaking......not sure if u have premix still or not.

gasket on your premix? what s that? you mean the gasket on the oil block off plate? on the 787 I shouldn`t have any oil leaking from there...

to answer your question, sigh, no I didn`t find the leak, bottom of engines were dry, nothing running down alongside the engine or starter... the oil that was on the rear of the engine bu the rear mount bracket have no idea where that came from. all hoses had clamps and a saftey zip tie... nothing jumped out at me to show cause of the leak, and the PTO coupler is dry... :banghead:

 

[Albysure]

If yours is blocked off then yea its not gonna leak there....I still use the oil injection system....premix. I don't see how u got fresh oil leaking if your premix system is gone...do you store a gallon of oil back there....no exhaust leaks or anything?

 

[Guest_User]

If yours is blocked off then yea its not gonna leak there....I still use the oil injection system....premix. I don't see how u got fresh oil leaking if your premix system is gone...do you store a gallon of oil back there....no exhaust leaks or anything?

true, the oil injection is gone, and I premix. oil nozzles are capped. everything else is dry... I don`t see why or where it could leak from... driving me nuts... there is oil in the oil tank to feed RV shaft, and those joints/clamps are secure...

 

[Albysure]

Yea you got me....gotta be a dried out oil line...just run your hands around all over were the oil leads to...gotta be wet ...

 

[griz400]

ive seen em leak at the line where it goes to the fitting,the 1/2 tygons, even if u have a new clamp, and if u dont have thread tape on the fitting, it will probably seep oil, expecially after engine gets warmed up and that oil thins

almost have to be there, since its the same height where u see oil at rear, and its "clean" oil, anywhere else would be dirty oil --

 

[Guest_User]

Yea you got me....gotta be a dried out oil line...just run your hands around all over were the oil leads to...gotta be wet ...

all lines are new, all clamps are new...lol

ive seen em leak at the line where it goes to the fitting,the 1/2 tygons, even if u have a new clamp, and if u dont have thread tape on the fitting, it will probably seep oil, expecially after engine gets warmed up and that oil thins

almost have to be there, since its the same height where u see oil at rear, and its "clean" oil, anywhere else would be dirty oil --

the fittings are sealed. this looks like someone poured oil down the back of the engine... I had thought the dam plug came out of the balancing shaft gear case, but that`s tighter than a frogs butt. the oil was all over the PTO carb, and the back of the airbox... like someone squirted it with a hose... those lines are not under pressure, the oil is gravity fed. and it def was new XPS oil for sure...
while running, there is no indication of where the leak is... weird I know... wow...

 

[Seadoobuddy]

You may want to tighten all the clamps again.....sometimes they loosen after the first run or two.
I found that to be true after I replaced all my fuel lines.
It was a bit hard to start, so Tony suggested I check all my fittings and most were loose including the pulse line.

Also I had an oil drip from my tank because of a dried out grommet at the bottom, replaced it and no more drips

 

[Guest_User]

You may want to tighten all the clamps again.....sometimes they loosen after the first run or two.
I found that to be true after I replaced all my fuel lines.
It was a bit hard to start, so Tony suggested I check all my fittings and most were loose including the pulse line.

Also I had an oil drip from my tank because of a dried out grommet at the bottom, replaced it and no more drips

Hi SeaDoobuddy, wish I had taken better pics, That`s the first thing I checked when disassembling. each new tygon oil hose had a new SS clamp, and a metal tang zip as a back up. first thing I did was wipe each fitting and hose connection with a white rag. They were all dry. Under the engine was dry. I know hard to believe, but with only 22 hours run time this season, it`s plausible.
The oil seepage from the tank grommet was minimal... that would seep when the temps of the day got hot and the oil expanded, pushing the oil, or making the grommet soft, take your pic... not even a split hose, nodda, I was all over the new parts installed...

this pic is where the oil was laying, and dripping down towards the balance shaft side of the engine. upon further disassembly, oil was all over the PTO carb and backside of the airbox... This started on the second to last ride of the season, or at least when I noticed it the most, and I`m all over these engines pre and post rides.

if you had an oil leak in an automotive engine, most likely the cooling fan or moving air would spread the oil leak around, and for the most part automotive fluids are under pressure and flow. That`s what this looks like, but no pressure, and no air movement like a cooling fan spinning at 3K rpm to spread the mess...

I`m forced to use new hose/different clamps and keep a vigilant eye comes the new season...and hope it remains dry...

crazy, isn`t it...