My gas tank appears to be leaking engine oil

[rphillips]

Oil consumption without leaks, kind'f odd for a GS. They're not really known for burning oil even after many many miles.

[Noreg]

50 mph wind, from riding a bike, will blow oil where you wouldn't think, from where you wouldn't think. Tightening the tach cable?? there are 2 or 3 seals & "O" rings in that little rascal. It takes a whale of a (very baaad) oil leak to make the eng. show low of oil within a few hundred miles.

With the oil filter cover leak I had earlier I could have it leak almost nothing, or have it leak 0.8 litres in 500 kilometers depending on how I rode it. It feels like it leaks more now, but I think the oil is maybe just spread on a bigger area.

But I guess I will fill it up to F and do a scientific test. Sort of want to go to Senja, some people say its prettier than Lofoten where I spend a lot of my time.

[Big T]

After market Valve cover gaskets can be slightly off and that's all it takes to spew oil

I had one let go when I was coming back from Mt St Helens and it oiled my boot a lot. I had installed it about 6 months prior

Fortunately, I had an OEM spare on the wall. More fortunately, I swapped over to my GPz and finished the rally

[Noreg]

After market Valve cover gaskets can be slightly off and that's all it takes to spew oil

I had one let go when I was coming back from Mt St Helens and it oiled my boot a lot. I had installed it about 6 months prior

Fortunately, I had an OEM spare on the wall. More fortunately, I swapped over to my GPz and finished the rally

I am now thinking I can have my wife cut me a new gasket for it. I need to replace the bolts anyways, and then I can do a second attempt at removing the intake boot screws with proper JIS screwdrivers. The wait for a new one I am afraid will be longer than I can go without it. Then I could check the valve clearance too.

I am going to order a bunch of parts soon though, to get what I need for the winter fixing.

[Big T]

You'll likely needs hand impact driver to remove the intake bolts

[Noreg]

Well I found the leak...

https://i.imgur.com/iDnzqDY.mp4 <- with sound.

[Rich82GS750TZ]

Well, you found A leak. Did you ever clean it up, dry it, then spray foot power on the engine to see where other leaks may be? The tach drive seals are a pretty easy fix, just 2 parts you need. One is a flat type of oring with goes on the outside of the shaft that goes in the hole. One is like an oil seal that goes on the inside of the shaft. 23 (26451-45000) and 24 (09289-05002) on the partsoutlaw fiche.



Your pic also shows an eclectic mix of exhaust studs and bolts. That's gonna be fun when you go to remove the exhaust.

[Noreg]

Well, you found A leak. Did you ever clean it up, dry it, then spray foot power on the engine to see where other leaks may be? The tach drive seals are a pretty easy fix, just 2 parts you need. One is a flat type of oring with goes on the outside of the shaft that goes in the hole. One is like an oil seal that goes on the inside of the shaft. 23 (26451-45000) and 24 (09289-05002) on the partsoutlaw fiche.



Your pic also shows an eclectic mix of exhaust studs and bolts. That's gonna be fun when you go to remove the exhaust.

Did you see the linked video? When I rev it I can visually see the the oil pouring out of that.

The seals for the tach is already ordered and on the way, but like the cam chain tensioner that leak is not an urgent matter. I assume a visible stream of oil at anything higher than idle is. I don't really believe the tach is leaking, but all the rubber is rotten, so I'll replace them anyways.

I think cleaning it and then running it when it leaks this much doesn't make much sense, Ill change the cylinder head gasket (need to cut my own) and fix the tensioner, and then I can go hunting for more leaks.

Video is here: https://i.imgur.com/iDnzqDY.mp4

[Rich82GS750TZ]

Oh, sorry, no, I missed video first time looking at your post. You need a new valve cover gasket. That's leaking a lot. I think it's time to park it. But you still need to know if your head and/or base gaskets are leaking as well. You don't want to do all this work and only replace the gaskets that you THINK are leaking, or that are clearly visible at a glance. If you have to, having just done it myself, replacing base and head gaskets isn't is scary as it sounded before I did it. Warning, if you get in that far, you may want to put new rings in as well. You'll get really good at scraping off old gaskets. But I'm getting ahead of myself.

While the valve cover's off, you should do valve clearance check. Lots of posts on the forum about how to measure clearance, and swap out shims. Seek out member Steve and email him for his valve adjustment spreadsheet which will be a big help with the math and show what shims you need in vs. what you have in what locations. Ugh - I feel your pain.

You wrote cylinder head gasket. Are you sure that's what you mean. Video shows valve cover gasket (or more correctly, according to the fiche, Cylinder Head Cover Gasket) leaking. If you need to replace the head gasket because it's leaking, conventional wisdom states to replace base gasket as well, because it's likely to be disturbed when you remove all the bolts that keep the head on the cylinders. I would recommend OEM gaskets all around. Is there a reason you say you have to cut your own?

[Noreg]

Oh, sorry, no, I missed video first time looking at your post. You need a new valve cover gasket. That's leaking a lot. I think it's time to park it. But you still need to know if your head and/or base gaskets are leaking as well. You don't want to do all this work and only replace the gaskets that you THINK are leaking, or that are clearly visible at a glance. If you have to, having just done it myself, replacing base and head gaskets isn't is scary as it sounded before I did it. Warning, if you get in that far, you may want to put new rings in as well. You'll get really good at scraping off old gaskets. But I'm getting ahead of myself.

While the valve cover's off, you should do valve clearance check. Lots of posts on the forum about how to measure clearance, and swap out shims. Seek out member Steve and email him for his valve adjustment spreadsheet which will be a big help with the math and show what shims you need in vs. what you have in what locations. Ugh - I feel your pain.

I totally agree that I should do all of them, but I have a trip the 7th, and I am running out of season FAST. So I will cut myself a gasket for the head and the breather and fix the tensioner and cross my fingers I can make it to Oslo and back. After that I will probably run out of season in a a few weeks to a month, at that time I will get all the original gaskets and do a full-arsed job.

Rings? What is that refering to? o-rings?

Doing the valve clearance check is something I've been putting off, but I am excited about it, when I'm there anyways I should just do it. I also have new stainless bolts for the top. Then its just the front bolts and the cam chain left.

I really want to get done with the top ten newbie mistakes list. But I dread dealing with the gas tank...

Edit: Also if the previous owner used some low quality gaskets, they are living on borrowed time anyways, and Id probably be best off getting OEM for it all.

[Rich82GS750TZ]

Rings= Piston Rings

[Noreg]

Rings= Piston Rings

Ahh, I guess that makes sense. Anything else that... Err, if I am going to do that, I need the exhaust bolts out? Definitively a winter project.

I have never cut a gasket before, I am really curious of how it will turn out. I have the cork gasket kind that I saw someone else use here. My new gasket is supposed to be shipped the day I leave.

I also wonder if the rubber boots for the air box needs to be replaced, they are HARD to fit on the carbs (or I have unusually weak fingers).

But dealing with it all during the winter means next season will be great. Perfectly working bike from day one.

[Rich82GS750TZ]

You're a braver man than I. Having never cut a gasket, doing so and then taking a long trip is not something I would attempt. What I do know is that my first 3 attempts at properly tightening the valve cover bolts resulted in me over torquing the bolts and the gasket squished too mush and ripped. I got more and more mile before a leak each on each successive try. I'm on about 600 miles since I did it last so I think I'm getting the hang of it (knock on wood).

[Noreg]

You're a braver man than I. Having never cut a gasket, doing so and then taking a long trip is not something I would attempt. What I do know is that my first 3 attempts at properly tightening the valve cover bolts resulted in me over torquing the bolts and the gasket squished too mush and ripped. I got more and more mile before a leak each on each successive try. I'm on about 600 miles since I did it last so I think I'm getting the hang of it (knock on wood).

That sounds a lot harder than Id imagine. Ill use the torque wrench.

I have road side assistance and I could always take a train or hitch hike down if I have troubles (pick bike up with trailer later).

If I get the head off tomorrow I can have the gasket ready before the weekend and test ride it in the weekend. I've been wanting to do a run down Sweden.

And if nothing works I guess Ill have to use the car, but that would be boring.

[Rich82GS750TZ]

Oh I made sure to torque valve cover bolts to spec with an inch-lb. wrench. A little less the second time. A little less still the third time. Don’t recall where I ended up the 4th time, but I know I wrote it in my service manual.