Oil leak 787 rotax 1999

[Speedster DL]

How would I know where the leak into the engine maybe either inner crankseal or the rotax oil injection? I am a novice... One is a ten dollar fix the other means a new engine... Right?

 

[mikidymac]

If there is oil leaking into the hull and making a mess it's typically the hose connections to the engine or oil tank.

If the engine is flooding with oil and hydrolocking or smoking a ton when started it's typically the inner crank seals.

 

[Speedster DL]

Thats my fear... Its hydrolocking ... And when i take out the plugs, oil comes out of both pistons... Didnt know if that may be a signal for one ir yhe other.. crank seal or the rave valve seal?

 

[brushmore]

Sounds like the crank seals. One way to tell would be once you got it running again, pinch off the oil supply lines. If the cylinders aren't filing up then it's the seals. In fact, some people put a valve on the supply lines to squeeze a little more life out of the engines before a rebuild. I wish I would have known that before I bought my boat.

 

[mikidymac]

I personally have never seen the rotary shaft seals leak but it does happen. In all my cases with it, it's always the crank seals.

The valve can buy you some time but never forget to turn it on.

Lastly some people have had the crank seals leak when using the wrong blue TCW-3 oil and after flushing the system and switching to the correct API-TC full synthetic oil the leaking has stopped.

 

[Speedster DL]

Thank you all for the great advice... The engine has been purged if old oil... I will replace with recommended oil.... Would anyone know the size of the shut off valve... Or provide a link to purchase?

 

[mikidymac]

I would see if the new oil fixes the issue before messing with the valve and see how fast if at all it fills back up.