Small oil leak

leehebs · 08 May 2016, 17:45

I was out to run my Tonhatsu 90 TDLI over the weekend to clear the fogging oil out of the system , whilst putting the muffs on , I saw a small amount of oil , maybe less than a teaspoon full on the floor and a small drip on the end of the skeg. I traced it back to two small breather holes under the propellor housing below the oil fill screw. Any idea please , boats not been used over the winter cold seal,s over flow with having been stored leg up ? ( avoids the local free roaming sheep using it as a scratching post.)

Thanks in advance for any help. Don,t have a marine engineers close, so I do everything myself if I can.

leehebs · 14 July 2016, 08:36

No one any ideas, still trying to sort it out or get some one in to look at it, just left the boat on the trailer. I take it there are oil seals inside the prop housing are they easy to change if I just drained the sump and changed the lot.

Would the seal shrink over winter with the boat being out side

jeffstevens763@g · 14 July 2016, 08:45

sounds like an oil seal try and get a manual off the web also try you-tube D RAY'S SHOP changing gearbox oil seals he has some good vids that might help.
your sure its not fogging oil thats been spilled in side the engine cover and trickled down the leg or two stroke oil or DWD40 if you use it?

hope that helps cheers

leehebs · 14 July 2016, 09:26

That help a lot thanks, off to look at the vids. I did wd and fog oil it all before winter set in and then in the spring, I will double check. I ran my finger down the skeg and there is still a smear of dark oil. It's great living out on the islands for boating but a pain for repair and parts , many thanks again.

willk · 14 July 2016, 09:50

It should be fairly obvious if you're dealing with gearbox lube, or a mixture of unburnt two stroke oil and fogging oil. I'd expect to see some old oil dripping from the exhaust - just not a lot! Gear box lube on the ground is a no-no! First thing I'd do is drop a bit of gear lube into a pan and check it for water ingress - it should run out as clean oil, not a cloudy emulsion.

Another thought - is there a 2 stroke tank inside the engine housing? If you filled it and tilted the engine then some may have run down inside the housing and leg?

leehebs · 14 July 2016, 10:13

Nothing from the exhaust out let. There are two small hole right at the bottom of the leg, where the prop shaft is, that's is where I find traces of oil, about enough to show on my finger tip as I wipe the skeg where it runs down to and a few small drips on the floor.

I do have an internal oil tank.

As I tipped the leg to take the photo I got about a thimble full flow out of the hole

jeffstevens763@g · 14 July 2016, 10:17

if its dark oil and the gear oil is ok as willk says its spillt oil picking up exhaust soot when it ran down the leg it dosn't take very long to spray a teaspoon of WD that would pick up any oil residue when sprayed giving the impression of a thicker oil. check your gear oil job done if ok

cheers

jeffstevens763@g · 14 July 2016, 10:22

Quote:

Originally Posted by leehebs

Nothing from the exhaust out let. There are two small hole right at the bottom of the leg, where the prop shaft is, that's is where I find traces of oil, about enough to show on my finger tip as I wipe the skeg where it runs down to and a few small drips on the floor.

I do have an internal oil tank.

As I tipped the leg to take the photo I got about a thimble full flow out of the hole

thats the leg drain lowest point i would expect that any spills would accumulate there until you tip it, if you took the gear box off you would probably see where the oil/WD ran down not suggesting you do that unless you want to but a quick check of the gear oil will put your mind at rest

leehebs · 14 July 2016, 10:36

Thanks, I will get some new oil ordered form the mainland. I take it the only way to check the level is to refill till it gets to the top screw drain

Fenlander · 14 July 2016, 10:39

Agree with Jeff... that's so likely to be either oil that's dropped out of the exhaust gasses and collected... or the long shot if there there was any way a leak on the 2-stroke oil container could run down inside the leg and pick up combustion deposits.

In my experience leaking gear oil rarely has any black to it... either golden... or milky if water ingress.

jeffstevens763@g · 14 July 2016, 10:57

i would crack the bottom filler first to check oil it wont run out very fast as its air locked if its golden its all good if its milky you have water in it could be a seal or it could be getting in through the filler screws if washers are old or it can be black i think its exhaust gases getting in seals again not sure how that happens though,good point from fenlander re two stroke oil if its not been burning all the oil, but my bet is its just spillage.
if you do the gear oil change, both plugs out drain fill from the bottom hole till it runs out the top put top plug in then the bottom job done, if you are doing the seals[hope not] fill whilst it on the bench lot easier.

cheers
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willk · 14 July 2016, 12:12

Quicksilver Performance gear lube is blue. Many others are brown/gold. None should be opaque/cloudy/milky. You can remove a very small amount of gear lube as Jeff says. Top up by filling from the bottom - but you really should be changing it every 12 months anyway - checking the old lube for metal flakes, water ingress etc...

leehebs · 14 July 2016, 12:45

I have been meaning to change it all spring, but wanted to get this leak sorted out first. Many thanks to all. I really wanted to get it sorted as one of the other on the island with a bigger rib wants me to to go with him out to St Kilda, I can see it from up the road but never been out there 35nm