Leaking Oil worry ?

Now this question is due to my unfamiliarity with motorcycle engines, perhaps a silly question, but I need to know, as what I found today is burrowing into my worry zone, my mind is thinking of crank shaft oil seals and how to fit them without taking the engine apart. But it might not come to that, as I am aware the worry has set in and is making me think of the worst case scenario. Just to note, I have replaced crankshaft oil seals on a two stroke before without splitting the halves.

Ok, today whilst I was touching up any frame part I had missed with my black paint, I noticed the blistering paint on the front sprocket side of the engine, the paint where I assume road spray has contacted the front of the engine, the black paint is crumbling off, obviously no etch primer has been used there, so I undid the 8mm hex head chromed screws holding the side cover on, so I could wire brush and paint, on undoing these screws, I noticed an oil drip coming out of the loosened cover, quite a flow at that, so I quickly scrubbed, slopped on paint and did the screws back up again, the drip stopped.

So, perhaps you can see my worry, as far as I know, there shouldn't be any oil in there, unless a failed oil seal, or could it be excess lurication from the timing chain. Is it normal to find oil under that cover, or am I worrying about nothing ?

Hi Sprocket. On your bike, you should not have to split the crankcse to repalce the greabox or clutch side oil seals. Only if a bearing. Sounds to me your gearbox oil seal is well worn. Here's how to replace it (if you konw already, may help those who don't):

Removing the sprocket is nicely dealt with incl pics in Rogerborg’s bike-in-a-box blog in the Monday 13 April 2009 entry ‘Replacing the Sprocket’: http://bikeinabox.blogspot.com/2009/...-sprocket.html

While the bike shown is a Huoniao, the procedure should be the same as your bike.

There is a knack!. :icon10:

After you take the sprocket off, note which face of the seal faces outwards and check if it lies flush with the casing or is recessed.

I prefer to put a screw into the metal body of the oil seal (may have to pre-drill first) and use a large pair of pliers to yank it out (it’s a push fit). Others use a flathead screwdriver, by sticking the end in the seal and levering against the crankcase and generally gouging it out – but you have to watch damage to the alloy surfaces, especially the seal’s seating.

Oil the inside of the seal (the rubbery stuff) and make sure no cr*p on it. Tap the new seal in using a light hamner with a piece of wood against body of seal (check it’s the right way round first!). Wipe off excess oil. Job done. :thumbsup:

Ah thanks davidqc, but panic over I think, looking on the Sundown Portugese manual, I notice one of the pictures concerning the area of worry shows the starter motor drive transfer gear with the residue of oil in it's machined recess and a glistening to the alloy casing quite dissimilar to the engine paint, also a pal said he has had bikes that had that without any problems, so worry over, and on the Sundown manual, I can't actually see an oil seal fitted to the crank shaft on the generator side of the engine. So without a seal, oil is meant be in there, but curious, a generator rotor and stator half immersed in oil, new one on me.

Another thing, the starter motor tansfer gear shaft is not running in bearings, just close machined alloy recesses, lubrication has to come from somewhere, or the shaft and or gear will suffer friction problems without lubrication.

You see, I know mechanics, but M/C engines and their wiles are new to me, I am still learning, half my restoration of the below bike, is me taking it apart to satisfy my curiousity and get familiar where things are and how they work.

Hi Sprocket. Thanks for feed back.

Yep, bikes have their wiles. Especially Chinese ones. A lot are either a dogs breakfast of components or Franken-bikes. Horrendous...but very very interesting. :thumbsup: