GS1100 oil leak mystery

[rcoville]

Hi to all.

I'm a relatively new GS owner. First, this bike is an 83 GS1100 ES with about 35,000 km on it. Overall very nice condition. This one has a Lockhart oil cooler and full fairings. Here's what is happening:

About 2 weeks ago I noticed a small drip of oil under the bike immediately below the very front bolt where the head gasket is. A day or two later, there was more. I also noticed the lower fitting for the Lockhart unit's circulating tubes (which come out the front of the oil filter cover) had a coating of oil. I removed the fairings, dropped the exhaust system (Yoshi 4-in-one-header and pipes) and removed the line to find it had a small split in the back side. I replaced both lines, checked the tightness of the front bolt, de-greased the engine, and test-ran it. Better, but still leaking. Then I took it for a long run without the fairings and came home with a right pant leg sprayed to the knee with blow back.

Next, off to the dealer who checked it and advised a breather tube had blown free (old and shrunk was the way he described it). They replaced the tube, de-greased the engine, test-ran it and sent me on my way. They believe the head gasket is fine.

It is better, but I still have an oil leak somewhere (I get some blow back on the fairing, right-hand side) and when I park the bike, I get 2 or 3 drips under it. It seems to me there is oil blowing back high up on the engine. I do not believe it is either a head gasket or a valve cover gasket. Both look fine.

Suggestions? Ideas?

Thanks

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. rcoville,

The usual procedure is to thoroughly clean the engine then apply some spray powerd, like foot powder, run the engine, and check for the wet spot. Just about any little leak can get blown all around the engine and make it hard to pinpoint the source. You might take a close look at the tachometer send gear area on the front or the cam chain tensioner on the back. This assumes that the head, base, and valve cover gaskets are not leaking. I seem to recall that there is a valve cover bolt that oil can escape from and a copper crush washer can take care of that. Maybe one of the 1100e guys will chime in soon.

Anyway, I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and 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

 

[rapidray]

Hi rco! Welcome to the site. I race & build a lot of 1100 & 1150 engines & know them well. Call me at 714-356-7845 if you want some help without waiting for answers on the forum. Ray.

 

[Guest]

If you're sure the oil cooler is free of leaks I'd check the tach gear, valve cover gasket and the o-rings on the middle two front head bolts.

 

[rcoville]

Mystery solved, and thanks everyone for your help. It was while I was working through your suggested spots to look that I found the real problem.

It is the cylinder head cover gasket (Haynes terminology, which I assume is the valve cover gasket) with a wee pin hole on the right side of the engine, hiding on the inside, facing the spark plug. I found it this morning after working over the entire right side, de-greasing, and while running the bike to flash off the rinse, I noticed a faint atomizing coming from the area. At first I blamed the head bolt that sits WAYYYY down between the two right spark plugs, but after careful observation, I finally found the culprit. It is misting out at the gasket towards the inside, collecting in the well between the 2 right-hand plugs and then running / blowing everywhere on the right side. It explains why the left side is bone dry. When it runs out the front, it sits right where the front bolt is for the main head gasket, which is why I originally was thinking that gasket was going.

I haven't got a lot of hands-on engine re-building expertise, but my Haynes Manual tells me a little RTV sealant, a new gasket, and proceed diagonally to snug up the bolts (to prevent warping the cover) and I should be fine. If anyone has further thoughts to guide me, I would welcome them. Otherwise, I think I'll order a gasket and get my hands dirty.

R

 

[bonanzadave]

Ask Joe Nardy about some o-ringed bolts under the valve cover. They will leak and it shows up as if the valve cover gasket is leaking. Id search it out for ya but Id rather have him go over it again as Im about to do a valve adjustment.

 

[Larry D]

When is the last time the valves were adjusted ?

I'd get a new valve cover gasket, adjust the valves and throw the RTV as far as you can out the front door.

 

[BassCliff]

When is the last time the valves were adjusted ?

I'd get a new valve cover gasket, adjust the valves and throw the RTV as far as you can out the front door.

Hi,

A agree with Mr. LarryD. As often as we have to check our valve clearances (every 4000 miles) you don't want to use glue on your gasket. It makes it very difficult to clean up before installing a new one. Use a thin layer of grease. Or, what I do is spray WD40 on the valve cover gasket before installing. It makes it MUCH easier to remove when it's time for the next valve check.

Actually, ever since my second valve check, I've been using a reusable Real Gasket (silicone rubber) on my valve cover. But these are not really recommended for your bike. Even though they are available for your bike, many have reported problems with the tach gear alignmnet when using a Real Gasket. It can chew up your tach send gears. Not good. Use an OEM gasket with some grease and maybe you can reuse it once or twice.

Thank you for your indulgence,

BassCliff