Leaking Oil from Johnson 2 Stroke
Hi Everybody,
I recently purcahsed a new 4.3m runabout and the motor is leaking oil out of the leg: where the prop meets it. It was like it when I bought it, so no issue there as I was aware and got a great deal.
It is a Johnson Endeavour 35hp 2 stroke 2001. One of the first auto mixing 2 strokes that came out. That has been disconnected a long time ago as it caused dramas so just running it as a standard 2 stroke oil mix.
I do know there is only really two issues that could leak oil. Either a bad fuel mix not burning off or a leaking gear box. Originally we thought it was bad fuel mix (crap oil used and the mix was looking terrible when I disposed of it). But what seems strange is that the oil leak seems to show up well after it was last used. It isn't that afternoon or the next day. In this case we took it out Sunday last week. The leak has only shown up yesterday. 8 days later!
Has anybody else seen this before or come across it? I am thinking it is prob just the gear box: pretty easy to rebuild and seal. But I am just stumped by it taking over a week to leak......
Thanks for any ideas.
The Saint
Posts: 456
Date Joined: 30/01/13
Are you sure it's gearbox oil
Are you sure it's gearbox oil ?
Gear box oil has a pretty distinctive smell, unburned 2 stroke oil is usually quite black.
I would think it's most likely unburned 2 stroke oil. Are you using a quality marine 2 stroke oil ? Is the fuel/oil mix the correct ratio ?
Also check that the thermostat isn't stuck open or removed, running too cold can cause the problem.
Brock O
Posts: 3163
Date Joined: 11/01/08
Mines a 95 with VRO still in
Mines a 95 with VRO still in operation but I have witnessed this before.
Same as Saint...Quality of oil does help IMO, I believe I had a coil on its way out at the time affecting performance also.
Sulo
Posts: 256
Date Joined: 13/08/11
Black or gold / honey
Black or gold / honey coloured oil??
If it is black it is 2 stroke oil slowly dripping through the exhaust system... (it may take a while to get enough to spill over hence the delayed time frame), Honey or gold coloured oil will be a leaking gearbox seal.
TCW3 oil is pretty much rubbish oil by nature (grade) while I agree some seem better than others all of the mineral oil types are pretty much the same. Only difference these days is synthetic blending.
North Coast Marine
Posts: 74
Date Joined: 23/05/16
Hey mate, I would be looking
Hey mate, I would be looking at your thermostat, if the motor is running too cold there won't be enough heat to burn off the oil, I did my apprenticeship at an evinrude dealer, that was the most common cause
Zano_1980
Posts: 8
Date Joined: 09/11/13
Cheers
Yeah, it's definately a black oil which is why I always thought it would be 2 stroke oil. The mix is at 50:1 so should be spot on. I ditched the crap that the old owner had in it and started fresh. Using a good Caltex oil. Previous guy was using Valvoline which I know is terrible.
Thermostat def sounds like a good place to start. Cheers guys. Will check that out. If it doesn't fix it, will have a look at the coil.
Hasn't affected the performance at all of the engine. Not one bit, so I am def leading to just unburned oil.
Thanks again.