Is this the infamous oil leak? 77 GS750

[Guest]

Hello. Bike is a 1977 GS 750 in perfect condition. A couple of months ago smoke started to come from one of the headers, pretty much when in idle or at a stop light. The second one close to the tach drive. I replaced the tach seals and today did an oil change. runs great. And again when at a light smoke... cleaned everything and checked and here are some pics so you guys can help me get her to the smooth condition she was :-)

[Brendan W]

Get the tank odd and have a close look at the valve cover gasket in around the chain tunnel.
A leak in there will emerge over the exhaust ports by 'magic'

[Jordan]

Anyone? Thoughts and help please Thanks.. Here is another pic.

[Jordan]

Get the tank odd and have a close look at the valve cover gasket in around the chain tunnel.
A leak in there will emerge over the exhaust ports by 'magic'

Thanks. Any other thoughts by looking and the second picture?

[850 Combat]

The chain flings a lot of oil at that gasket right in the center Brendan is right, and you probably need to check your valve clearance anyway.

In my personal experience, it is OK to use an aftermarket valve cover gasket.

[greg78gs750]

yep, really hard to tell where the oil is coming from, clean it up, check the valves,etc

[chuck hahn]

Clean it up and spray the head gasket area with some aerosol foot powder. Start it and then watch as the exact spot of the leak will appear by discoloring the foot powder an oil color. The foot powder will wash off.

[Jordan]

Clean it up and spray the head gasket area with some aerosol foot powder. Start it and then watch as the exact spot of the leak will appear by discoloring the foot powder an oil color. The foot powder will wash off.

Thanks. Will do it. And then post the result

[mrbill5491]

What's up with the different exhaust bolts?

[Steve]

The second one close to the tach drive.

Just so you know, ... the two cylinders in the picture are #3 and #4. Cylinders are numbered from left to right, as you sit on the bike.

#1 is under your clutch hand, #4 is under your throttle hand.

.

[Buffalo Bill]

These silicone gaskets work REAL good. Forgot when I put one my bike.
REAL gasket

[Nessism]

I hated the Real Gasket I bought for my 850. It's too soft and squeezes out too much when you tighten the bolts even hand tight. Get an OEM Suzuki valve cover gasket and check the valve clearances while you are at it. There is no way for people over the internet to diagnose an oil leak on someone's bike other than to tell them to go back to basics and make sure all the possible gaskets are sealing.

[Jordan]

Thanks for the replies... I hope it is those gaskets you guys mention... because now I have black smoke... when I rev it. Took it to a shop and as you know many shops wont work on our oldies. The guy gave was very nice and gave me some good pointers. One of the reasons he said he wouldn't work on it as MrBill mentioned and I noticed when I got her was the bolts, if you look at the picture I posted up close the diameter of the bolts is different on the 4th and there is also some kind of I dont know, glue? Around the one that is a 10mm... so any thoughts are welcome

As for causes for the black smoke on gs I am also opened to comments.

So I am going to start checking the sparkplugs and go from there. Cant find the source of the leak. I mean I know it is cylinder 3 but I guess I will have to clean it again amd try with the baby powder.

Thanks again for you time to read this. It helps

[Mickeymoe]

i had the same problem with an '80 GS850G many years ago. Turned out that the tach cable kept loosening up from vibrations. I realized that should not allow oil to leak so I remember replacing an "O" ring inside the tach cable drive and that fixed it. Used a spot of thread locker on the cable threads and my problem was fixed. This may have been mentioned in the thread but if so I missed it. Good luck.

Mark

[Jordan]

i had the same problem with an '80 GS850G many years ago. Turned out that the tach cable kept loosening up from vibrations. I realized that should not allow oil to leak so I remember replacing an "O" ring inside the tach cable drive and that fixed it. Used a spot of thread locker on the cable threads and my problem was fixed. This may have been mentioned in the thread but if so I missed it. Good luck.

Mark

I replaced all those, the seal , the "O" ring... and it did not fix it... it doesn't have a tach anymore. will continue to try to find the source. any comments on the black smoke??

Thanks