Oil Leak

[Guest]

Hey guys. I've been lurking this forum for the last few weeks. I'm a new rider and I bought a 1982 GS850G as my first bike. Using the forums here I've managed to work on a few minor things. I'm now having an issue that I couldn't find directly addressed here so I was hoping for some advice.

If if you see the attached photo for reference it will help. This is from the Haynes manual page 118. I'm having some oil dripping from the rear side of part 5 dust cover. I'm assuming this is engine oil? What does this dust cover do? Is this just covering an internal piping or does the oil flow directly through the rubber boot?

Any by suggestions on how to diagnose and fix this leak? I'm worried about pulling out the boot and dumping oil everywhere. I am a pretty green mechanic so assume I know nothing haha.

Thanks for any help you can give this noob rider!

[ShadowFocus603]

That dust cover just covers the joint between the engine and drive shaft. If you are leaking from there I'd guess it was gear oil from the secondary unit getting past the rear output shaft seal.

[JTGS850GL]

It may also be engine oil that's leaking from some other location and just dripping at that point. Probably an oil pan gasket leak. Your best bet is to do a thorough cleaning of the entire engine and related components and then start looking for the leak.

[MisterDrew]

You guys were right. It's leaking from somewhere above that gasket and just dripping down it. I haven't been able to find the source though. It is so hard to see in there without taking everything apart...

[MisterDrew]

http://imgur.com/a/RIknY

ok I found the source. This black rubber tube. I pulled it out the side so you could see which one it is. It was sitting directly above the rubber dust cover before. I included pictures showing where it goes to the engine. I think it connects to the top of a carb? What does this do? What can I do to fix it?

Thanks!

[BigD_83]

If it is oil coming out of there then it might be the puke tube, also known as the breather vent hose. Follow it carefully. If it is the breather vent hose, it should attach at the top of the engine. They often have plugs to keep the escaping oil from dripping down onto the ground (and your bike).

[MisterDrew]

It's going into the top of the carb in the first picture.

[bwringer]

The breather tube is supposed to connect a fitting on the very top of the engine to the airbox. However, it appears to be some random piece of fuel tubing so you may have trouble getting it onto the fittings.


Here's the airbox diagram -- it shows the tube and the nipple on top of the airbox:

http://www.onlinecycleparts.com/oemparts/a/suz/50d401bef8700230d8b4e587/air-cleaner

Here's the valve cover (AKA cylinder head cover). There's a nipple at the rear of that piece on top (#7 on the diagram).

http://www.onlinecycleparts.com/oemparts/a/suz/50d401b8f8700230d8b4e57c/cylinder-head-cover

IIRC, this is 10mm tubing. For some dumb reason it's still very difficult to find metric tubing in the US, so you'll find that a lot of people resort to 3/8" tubing from the auto parts store, which is a little smaller and hard to install.


If that tube connects to the top of the engine, it does not connect to the carbs -- it's just been pushed between the carbs. It doesn't belong there -- the breather tube is normally much shorter, just long enough to reach from the breather cover on top of the valve cover to the nipple atop the airbox.

Here's what it normally looks like -- I couldn't find an installed photo, but this shows the connection to the engine and the other end hanging because the airbox has been removed.

[bwringer]

We may have misunderstood your photos -- is that tube in the first picture actually attached to a fitting between two carbs, or is it merely passing between the carbs on its way somewhere else?

If it's attached to a fitting on or between the carbs, it may be a bowl vent tube. And there should really never be anything coming from this tube.

[BigD_83]

I couldn't really see where the tube was going to and from in the imgur picture



However, if you have anything that is coming from the carb to that area of the bike, they would be the carb vent hoses and should be attached to the "Tees" between 1/2 and 3/4 carbs. There should be two hoses.

If it is free at the top of the carbs, and there is only one hose, then it is likely the breather hose as bwringer described. That breather hose should be attached at the top of the valve cover, EDIT- which goes to the top of the airbox, and from the bottom of airbox there is another tube free at the bottom of the bike. There should be absolutely no hoses connecting the carburetors to the valve cover.

[MisterDrew]

There are two both attached between carbs. Between 1&2 the between 3&4. They both go out to nothing and hang free on the other end. It appears they are both leaking oil. What is going on? Thanks for the help guys I'm in over my head here.

[MisterDrew]

Using your guidance and doing a little more research it seems it could be gas from the carbs of a needle is stuck? I hope this isn't the case. I just paid 500 bucks to Suzuki to disassemble and sonic clean and tune up the carbs a week ago.

[BigD_83]

Oh no. I'm sure you have read some of the horror stories of members taking their old bikes to modern dealers and getting less than stellar service. Don't dwell on them, but convince yourself you are not in over your head. YOu can solve the problems on your own, with the help of the members of this forum.

You should be able to tell the difference between a gas leak and an oil leak. An oil leak should be very thick, while a gas leak will be thin and won't glom dirt like oil. There should also be a smell of gasoline if the vent bowl lines are pouring gas. There really is no way for them to be moving oil.

On my 650, those vent hoses are long enough to stick out below the rubber boot in question, such that they couldn't be the cause. Your vent hoses may be different

When Suzuki did the service, do you know if they put on new bowl gaskets? Some of the ones available on the market are slightly too large, and can cause the floats to hang up.

[MisterDrew]

Thank you for the reassurance!

it feels like oil to me. It's viscous and dark. Unless it's old has slowly leaking I can't imagine it actually being gas... I'll see if I can get a second opinion at work today.

[MisterDrew]

I think they just changed the main carb gaskets.