80 gs1100e Oil draining from engine breather

[CincinnatiKid]

So I changed oil a few weeks back and a Surprisingly low amount of oil drained out.
Filled back up with Rotella T6.
in the past weeks since riding, I?ve been finding oil spots on the ground where I park the bike after a ride. Oil is coming out of the engine breather hose, which exits into a small filter that hangs right above the swing arm pivot.
Most of the time I?m riding less than 10 miles at a time in Chicago weather (below 35F), and the oil spot is small. Today I rode it hard for 30 miles on the highway and when I came back to the bike after work, there was about 1.5cups of oil that had been pumped out.

Initially I thought it was just bad quality control, and me overfilling the engine oil, but after weeks of this happening, it seems like something else is to blame. I checked the oil level after getting home this afternoon, and the level is below the F mark in the sight glass.

aside from user error and overfilling the engine oil, what might be causing this?
bad rings leaking exhaust pressure into the crank cases??
need to do a compression check this week, but it was good (all cylinders about 145psi or so) before winter.


will try to get some pictures up soon. The top of the swing arm is covered in oil, and the oil flows down the left side and drips near the rear axle while the bike is on the side stand.

 

[tom203]

Yes, a compression test is called for... But make sure your petcock has not failed and is dumping gas into #2 causing over pressure situation in crankcase

 

[CincinnatiKid]

copy that. i think the petcock is alright, but it's worth a check. gas mileage has been consistent during this whole experience.

while kicking it over in my head, i think i may have figured it out (hopefully). the aforementioned oil change was brought on by an unsightly leak on the breather cover. there was about an inch of gasket failure, and it was dribbling oil out the left side of the cover, and going absolutely everywhere behind and below it.


the gasket came off in mostly one piece, and so with the cover, i was able to make a pretty good re-production of the way the previous gasket functioned, using some gasket paper and a sharp utility knife.



it fixed the external leak, i did the oil change, i rode away with a new problem, which is this oil-from-the-breather issue.
everyone on here talks about OEM GASKETS OR DIE, so i thought it was worth a shot to look into it.

that's the NOS gasket. obviously looks a bit different, and hopefully once i get that installed later this week, it will help keep flung camchain oil from finding the breather hose.

fingers crossed. in the mean time, i got a compression check to do. so if you'll excuse me.....

 

[CincinnatiKid]

also something that is very cool is that it appears that my base gasket has developed a small leak below the camchain tensioner.

:encouragement:

 

[fastbysuzuki]

First I would make sure the filter on the breather is clear any restriction here will increase crankcase pressure if that's clear then it is time to do the compression test (warm engine and throttle held wide open) then post the results.
a decent home made gasket should suffice for the breather cover.

 

[Steve]

... it appears that my base gasket has developed a small leak below the camchain tensioner.

Before you do anything crazy, make SURE it's the base gasket. :-k

If it appears to be leaking below the camchain tensioner, make sure it's not the camchain tensioner.

It's a LOT quicker and easier to change. :encouragement:

.

 

[CincinnatiKid]

Copy, I did bassclif?s tensioner overhaul on my 80 gs750 because of it being leaky.
its such an oily mess down there, it?s hard to determine the source.

this is what the bike is doing today (which is the same as all days), pulling into the driveway at home after work. I thought this white smoke that was happening from the breather vent was because it was cold in the previous weeks, but it?s 41F here now.

 

[CincinnatiKid]

so if that first oil leak wasn't enough, today we're profusely leaking from the exhaust side of the engine.
we're parts shopping, ladies and gentlemen.
i was hoping to delay, but it's time for a rebuild. found a lead on a place in town that will do the machine work on the cylinders and head
any opinions on whether head resurfacing/removal to increase C.R. is worth the time/money?

OEM base and head gaskets
New rings at least, potentially new pistons/rings in a .5m Overbore
Camchain Tensioner rebuild/gasket
Valve Guides (Viton)
Cylinder/case o-rings
Exhaust gaskets

What else might I want to invest in @ this time?
(besides a working bike (or a bus pass) to get me to work and back!)

 

[Steve]

any opinions on whether head resurfacing/removal to increase C.R. is worth the time/money?

I don't have any experience in this area to give you any comparison numbers, but my line of logic says that by the time you remove enough material to raise the compression a noticeable amount, the cams will be a bit closer to the crank. The question would be whether that distance will be enough to affect cam timing. Slotted cam sprockets would rectify that.

.

 

[Guest]

sounds like more oil than one would expect from this, BUUUUT.....a leaky valve cover gasket or half-moons can get oil spraying in some pretty unlikely places. Before you tear it down I would clean it up and try to locate the leaks, there is a chance it might not be as bad as it looks....

 

[Rob S.]

And please, when it's rebuilt, no more exhaust tape!

 

[CincinnatiKid]

Had an unexpected few hours today to get a preliminary look-see. Cleaned it up with engine degreaser after a compression test, so tomorrow I can run t after spraying some talc powder on the front and around the engine to look for leaks. The compression test was pretty discouraging though.

cyl1 - 100
cyl2 - 0 ish
cyl3 - 100
cyl4 - 85

not sure exactly what happened in the 6 months since I last did the test... I certainly don?t abuse this engine in the ways that others certainly do!!

either way I have a shop waiting for me to drop the cylinders and head off for a hone and valve job. Rings and gaskets and valve seals on their way.

the goal is to get the engine broken down enough to drop the parts off at the shop tomorrow before the day is done.
wish me luck

 

[CincinnatiKid]

And please, when it's rebuilt, no more exhaust tape!

LOL these pipes are hella ratty underneath the wrap. I priced out a 4-1 Mac exhaust a few nights ago and it’s like 250-300. Not quite sure if it’s on the shipping list yet.

 

[steve murdoch]

LOL these pipes are hella ratty underneath the wrap. I priced out a 4-1 Mac exhaust a few nights ago and it’s like 250-300. Not quite sure if it’s on the shipping list yet.

I don't want to derail your thread but if/when you look for a new exhaust leave the MAC behind and spend a bit more for the Delkevic.
https://www.z1enterprises.com/delkevic-gs1000-78-80-4-1-s-s-exhaust-system.html

 

[CincinnatiKid]

thx for the link. what makes the MAC second tier? the delkevic looks sweet either way, and not that much more $$

things have stalled after a particularly abundant weekend/week/coming week of work, on top of a nasty tussle with whatever illness has been making the rounds recently.

found a great machine shop on a good recommendation out in the CHI suburbs. Fornarelli Motorsports, if anyone can vouch...

I have a day off on sunday to drop the engine out, soda blast it as clean as i can get it, break it down and drive the head and cylinder out to get work done.
pics of the breakdown to come.

also figuring on a fresh chain and sprocket set while the engine is out, etc etc.
likely will stay with the same ratio, but swap to a 530 setup.

 

[CincinnatiKid]

Rings..... yikes.

On Cylinders 1 and 2, the top 2 piston compression rings were extremely brittle, and cracked into pieces with light pressure. The smallest pieces of the rings were difficult to remove from the ring "trough" in the piston, but eventually they came out. they were stuck in the groove, had to be persuaded/picked out. there was no apparent damage to the piston, although they haven't been thoroughly cleaned and inspected. the oil rings were in relatively fine condition. The compression ring pieces had a cross section that looked more like a "T" than a rectangle. See the pic of the pieces on the magnet for detail.


https://i.ibb.co/5RrWZZb/IMG-8833.jpg (piston ring pieces)
https://ibb.co/pJmRrWt (magnet pieces)
https://ibb.co/Dttfpvy (pistons 2 and 3 comparison)

comparison of the 2 and 3 pistons shows that combustion carbon had found it's way past both compression rings on piston 2, which likely confirms the suspicion that blow-by was responsible for the initial complaint of oil exiting through the breather.

head and cylinder are at the machine shop now, new springs and seals for the valves, and a hone for the cylinders.
re-assembly in a week or two.

 

[CincinnatiKid]

any motor experts want to venture a guess at to what would have CAUSED such a ring failure?

my best guess is from a lack of lubrication, which caused a brittling due to excessive heat, which damaged the rings and their shape/characteristics.
the oil level was low when this all began. not frighteningly low, but low.

 

[Grimly]

Over heating, over revving, over advanced ignition, overly lean mixture.
Take your pick.

 

[CincinnatiKid]

i rebuilt it.
it runs nicely now.
i will break it in for a few hundred miles
then i'm gonna rip it.