Oil dripping from #1 exhaust port GS750EX

[BILLDIGIOIA]

My son and I are refurbishing a 1981 GS750E. The bike is low on power (little to no acceleration at 70+). plugs on cylinders 1 and 2 are oil fouled and oil is dripping from #1 exhaust port (where header meets head). Compression in No. 1 is 152, No. 2 is 160. Went through a half quart of oil in 40 miles. Cylinders 3 and 4 are clean, nice plug colors, 160+ compression. Valve cover is coming off later on today. Read about o-rings on some bolts, where do the bolts exit that they need to prevent oil from seeping through and how bad could the seepage get past the threads? Or is the area where the seepage goes before the threads? Any experiences out there? Have been riding GS's since March, 78. My first question on this forum.

[chef1366]

Sounds like bad rings and the extra oil is elevating the compression numbers.

[Roostabunny]

Chef might be right, but I was once sure I was leaking oil from the exhaust and it was actually a failed valve cover gasket on one of the inner edges. Was leaking down, pooling around the spark plug, then dripping forward through the cooling fins to exit right behind the exhaust collar.

Doesn't explain your other issues, but since you're taking off the valve cover, make sure to look for that possibility.

[chef1366]

By chance does the oil smell like gas?

[KEITH KRAUSE]

Might be a leaky valve guide seal.

[BILLDIGIOIA]

Love a mystery.

My first instinct is valve seals too, so I will double duty my leak-down tester to hold the valves up to check for valve guide wear and replace the seals. Bought this bike in October, only could hear it run, could not run it hard because of running gear, brakes, etc. non-functional. Our mistake but the bike looks rakish and we know the potential. Still, my son wanted a project, so now he really has one. Don't have any history, so don't know how long it has sat. Under 20K. Original pipes completely rusted out and rusted shut, all at the same time. By the way, a Kerker for a 78GS1000e fits this 81 750e like a glove.

I am temporarily discounting the ring theory until I check the easy stuff and because cylinders 3 and 4 are perfect. By the way no oil anywhere near the spark plug holes or on the top of head. I know how a simple leak can appear to come from everywhere and nowhere! Thank you to anyone and everyone who takes the time to post a comment here.

[BILLDIGIOIA]

Forgot to answer that the oil does not smell like gas.

[Nessism]

Half a quart of oil in 40 miles is BAD!!! There must have been a huge blue cloud behind the bike for it to burn oil like that. I don't think valve stem seals alone will allow that much oil to pass on a relatively low mileage bike like that.

Good luck and please keep us informed (including photos...hint, hint)

[BILLDIGIOIA]

Made a pneumatic plug to pressurize the cylinder so that I can service the valves, ie. check guides and replace seals without the valves falling into the cylinders, but now I need a line on a munchkin valve spring compressor, mine is too big and the one in the suzuki manual only works if you take the head completely off the bike. Will work on pictures. Son has fancy blackberry, dad gets second hand cell phone when wife and son are tired of theirs. As for the half quart, I don't have any history on this bike and that was the first oil change that we put in it, all I know is that a half quart disappeared over a very short number of miles, lots of smoke on startup, not much at all when the engine is hot.

[chef1366]

It's easier to just to pull the head.

[rideOn]

I had a similar problem. On long rides, my left pant leg had oil spots from the leak. After my first valve job and new gasket, no more oil spots.

[BassCliff]

Greetings and Salutations!!

Hi Mr. BILLDIGIOIA,

I just stopped by to cordially welcome you to the forum. Mr. Steve has a video on valve spring replacement here: http://s25.photobucket.com/albums/c9...Compressor.flv . I have gathered some information on my little website that you may find useful. There's also lot of knowledge and experience here in the community. Now let me say, "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[BILLDIGIOIA]

Viva La Revolution

Off with its head. Will be checking rings, decarbonizing, checking valve seats, etc., replacing seals for sure, other parts as we go. We are in this deep, may as well go all the way. Thank you for the warm welcome.

[Larry D]

It will look alot like this.....

http://www.thegsresources.com/_forum/showthread.php?t=151166

.....and this....

http://www.thegsresources.com/_forum/showthread.php?t=151315

[BILLDIGIOIA]

When I click on those two links, don't find any pictures of heads or disassembled engines. New question, cylinder block appears to be welded to lower case. Suzuki manual shows expensive expanding scissor tool being used to separate block from case. Hammer and block of wood have failed. Any other shadetree techniques out there?