Exhausts oozing engine oil, plugs are clean?

[Guest]

Hi friends.
A friend of mine owns a gs450. One of his spark plugs was misfiring as he was doing his engine break-in at relatively low rpms so he replaced the plugs and unfortunately for him, the plug that he put into his left cylinder was not functional. Now that he has replaced both plugs with brand new ones, his bike is running relatively smoother however there is visible power loss. His engine head gasket is blown and there is engine oil literally oozing out from the left exhaust however surprisingly for me, the plugs are totally clean which means there is no oil burning off in the cylinder?

I recently overhauled his engine top-end and put new valves + valve seals in it. Any suggestions?

[tom203]

".....Have the valve seals been ripped off due to enormous pressure created in the cylinder due to non-functional plug on one side?...."

There's oodles of more pressure when plug ignites mixture properly. You sure it's not an oil/gas mixture in left exhaust?

[Agemax]

if the head gasket has gone, and the left plug wasn't firing then oil would have filled the combustion chamber and then into the exhaust.
now it is firing and working (all be it badly, due to head gasket failure) what pressure is being built up by the compression stroke is now blowing the oil out through the exhaust.
tear the top end down again and rebuild it properly.

[rustybronco]

You sure it's not an oil/gas mixture in left exhaust?

With his plugs being clean, my thoughts as well.

his bike is running relatively smoother however there is visible power loss.

[safwan.khan]

Yes there is no engine oil in the cylinder and the plugs are super clean as they should be on an ideal engine. I'm going to rebuild the top end again today. Just wanted some suggestions regarding what could actually cause engine oil to leak down the exhaust when the plugs are clean and there is no oil in the chamber. After changing plugs the bike has run almost 15km and this is enough to burn the remains of gas trapped in the misfiring cylinder. Why is it still leaking engine oil (lubricant) down the exhaust? What's the possible path for that oil if not cylinders?

[Big T]

The head gasket is below the exhaust port, so

I'm guessing you mean the valve cover gasket?

The valve cover gasket is leaking oil down on the exhaust

[safwan.khan]

I'm going to replace both the valve cover gasket as well as the cylinder head gasket along with valve seals just to be on the safe side. Still scratching my head though as the engine oil was literally pooling around the exhaust tip and the external area of both mufflers is totally dry so it came from inside.

The head gasket is below the exhaust port, so

I'm guessing you mean the valve cover gasket?

The valve cover gasket is leaking oil down on the exhaust

[rustybronco]

Yes there is no engine oil in the cylinder and the plugs are super clean as they should be on an ideal engine.

Spark plugs are never 'super clean' unless fuel has washed all the colour off. They will always be somewhere between a light grey, tan or brown on a normal engine.

[safwan.khan]

Well that's what I meant when I used the term super clean :-)

Spark plugs are never 'super clean' unless fuel has washed all the colour off. They will always be somewhere between a light grey, tan or brown on a normal engine.

[rustybronco]

There is quite a difference between 'totally "clean" and a normal looking spark plug.

If you have oil coming out of the exhaust, dripping as it were, then there WILL be a indication of oil usage on the spark plug(s). Oil cannot introduce it's self down stream of the combustion chamber. There is no path for that to happen.

If a cylinder is firing and there is oil coming out of the end of the exhaust system, there will be smoke as the oil is being burned in the combustion chamber.

Does the engine smoke?

If it does, then there will be evidence of it burning oil on the spark plugs as long as they are of the correct heat range and no anti-foul adaptors are used. If it doesn't, then one of two possibilities will have to occur. One, the cylinder is not firing and the engine will be considerably down on power and the engine oil level will have to drop for it to have oil dripping from the exhaust. Two, it is not using oil and therefore no oil will be coming out of the exhaust pipe and there will be no loss of oil from the crankcase.


The most likely scenario is, fuel, mixed with carbon, is what appears to be at the end of the exhaust pipe.

Does the crankcase smell like petrol?

Has the oil level in the crankcase increased or decreased, or is it about the same level?

Yes it is possible that the valve stem seal(s) were damaged upon installation and there is a issue with the head gasket leaking. A head gasket leaking externally will not introduce oil into the exhaust stream, and burning enough oil to have it drip out the end of the exhaust pipe, will notify anyone within 5 Km.

Regards,

[safwan.khan]

I am back with some pictures. Looks like the exhausts are not the only place where the oil is leaking. It is leaking all around the front part of the top end of the engine as can be seen in these pictures.

https://www.dropbox.com/s/xlnnl2h8m2zoiud/IMG_20140302_202542.jpg

https://www.dropbox.com/s/idojzt4hsf5ke36/IMG_20140302_202528.jpg

[safwan.khan]

Guys I have a hunch that I've figured out the problem. Please correct me if I am wrong.

There were no oil separator screens installed in the cam case breather area so I took a piece of wire gauze and moulded it to the size of the fitting and seated it in there. Before that there was oil dripping from that part however now there is no oil leak from that breather. But when the bike starts, the oil starts leaking from near the exhaust outlets of the head. It seems like a blown exhaust seal. Also, I found that there is a bolt fixed into what seems to be the crank case breather of the engine (I'm not familiar with the location of crank case breather on gs450s so just guessing) which seems to make a story that fits together well. Here is a picture of that bolt on the engine.

https://www.dropbox.com/s/zdvxm88t5h5qgvc/IMG_20140303_080914.jpg

Just for reference, here is one of the spark plugs. Both look 100% identical so just showing one here:

https://www.dropbox.com/s/x8qgd5yszu85pxo/IMG_20140301_083851.jpg

[tkent02]

Not the breather. That's the neutral stopper.

On the four cylinder bikes, the breather is a tube coming out of the small breather cover on top of the valve cover.

[GSX1000E]

I just looks like the USUAL tach drive leak that all of these bikes eventually get to me. Just order number 23 & 24 here from your closest Suzuki store:

http://www.partsoutlaw.com/OEMpartfinder.htm#/Suzuki_Motor_of_America%2c_Inc/GS450ET_(1980)/CYLINDER_HEAD/02520001/5602520003

Replace those parts and clean up that mess.

[safwan.khan]

Oh.. so my guess was wrong!
Thanks a lot for correcting me. But now where do I stand with the problem? Should I take apart the cam cover and adjust the top breather again? What I did was, I took off the hard cardboard like cover that is under the top metal head which I took off unscrewing the top 4 bolts. Under that, there was a deep housing from where oil comes on top. I filled that space up with wire gauze and slapped it back shut. I now realized that I only had to do it the way it is shown here instead of filling the entire thing up with wire gauze:

http://www.ebay.com/itm/1981-SUZUKI-GS450L-crank-case-breather-OEM-11176-47010-/201043069517?pt=Motorcycles_Parts_Accessories&hash=item2ecf19ca4d&vxp=mtr

Not the breather. That's the neutral stopper.

On the four cylinder bikes, the breather is a tube coming out of the small breather cover on top of the valve cover.