GS550E 1980 engine leak Crankcase or where ?

[ukjules]

Run engine at low revs till warm
and no leak signs.


will go higher revs long run when stops raining !

 

[Rich82GS750TZ]

Don't ride too far before you stop and take a look. That leak will show up . Be sure to look hard at the automatic cam chain tensioner gasket on the back side of the cylinders under the intake boots, and the tach drive where the tach cable enters head or valve cover (varies by model)

 

[ukjules]

Not run the bike to hot yet or done a 3m
run to check due to rain.

But I can confirm there is oil around the cam
chain tensioner gasket.
There is oil around the tacko drive on rocker
cover.

can a oil leak around the cam.chaim tensioner
and tacko drive really produce what I am seeing ?
I.e. oil loss ?

clearly not the splash of oil on the front bottom left?
as for that I can see no leaks whatsoever in that area
but it run ot hard yet.

- ill check the breather area and see if it's working.
- will run bike to see if j can see any leak on alternator
cover and lh front.
-ill clean entire engine to include rocker over ,
tacko and cam tensioner and use the spray powder
method

 

[ukjules]

lh side rocker cover.

But this cant be the leak ?

 

[Rich82GS750TZ]

It's probably time to check valve clearance anyway. and overhaul the tensioner. Good quide on BikeCliff's Website. Get OEM gasket for Valve cover, and tensioner. Replace oring and oil seal in the tach drive.

Unless you can pinpoint it to leaking from one place, looks like you got multiples.

Though, looking at the pic of the tensioner, It looks like the head gasket may be all wet too. This is why you have to see where the powder gets wet first. Because after the initial drip, it runs all over.

 

[Brendan W]

View attachment 61930

lh side rocker cover.

But this cant be the leak ?

It's one of them
I had a bad one in there once. On the 850 it can make it's way forward under the cam and end up on the front.
Air does weird things in there.

 

[ukjules]

It might be one of them but you would agree
it would barely show up using any oil?
It surely is a unsightly leak but no way the
200mile 1litre cause ?

 

[Brendan W]

It might be one of them but you would agree
it would barely show up using any oil?
It surely is a unsightly leak but no way the
200mile 1litre cause ?

Say you average 40mph. That's five hours running or 3 1/3 cc per minute.
Hard to see that coming from there but it's surprising how a few little ones can add up.
Anything from the front yet or has it stopped raining?

 

[ukjules]

Rain and cold stopped play.
Will start again tomorrow on te first powder dusting
test on front left.

remember engine clean on right (as you sit on it)
but oiled front left? with the seepages
on the cam tensioner and some on rocker cover.
(which I have lived with as never thought they
could make oil go to front.

the powder spray method iv never tried so I
have hope to find the culprit.

 

[ukjules]

Update:

4m run to temp but not full revs.
Zero oil on powdered front left.
Zero seepage

Pic shows some discoloration of powder
around head gasket front protruding bit.
I assume this discoloration is what we are looking
for for leaks.

- checked the top of engine breather.
Zero pressure coming out (or in)
what does this mean?

(I agree it is prob time for oem head gasket up
and clearances etc but I will push a bit
to see if I can find leak.
looking at my notes :
2015 new stater gasket
2016 new stater, base , head , cam cover gasket
2018 valve clearances
2018 re check state bolts and length

so from 2015 the leak has been as it is now !
no worse.

 

[Brendan W]

There should be something coming out the breather.
I'd take it off and see if those scrubber pads are clean.

 

[ukjules]

Ok. I will do that tomorrow.

Sorted the gsx and RD
to take over for the winter ...so the
GS can be sorted whatever it needs.

When you saying soming should come out.
is it a gentle flow or a gust ?
Does it increase with revs ?

 

[Brendan W]

When you saying soming should come out.
is it a gentle flow or a gust ?
Does it increase with revs ?

Might be just a wisp at idle but definitely increasing with rpm.

 

[uk gs nut]

With engine stopped remove oil filler cap, get some air blowing in there. You should hear air in the air box. That should tell if the breather is clear. The pipe from head to airbox can sludge up.

 

[ukjules]

agh ok. out with the diving cylinder
tomorrow ....to blow air through.
Good idea.

Also continue to find leak .. so might have
to clean whole engine more thoroughly
for powder tests.

 

[ukjules]

Update:
Air through oil filler and out of
breather pipe = confirmed ok.
No blockages in pipe.

plan - tomorrow will do a compression test
and supply results for you all to assess
along with data from 3 years ago same test.

 

[ukjules]

Compression test:
Details attached for wet and dry test.

I think you are meant to do it with
throttle fully open ?
Assume on this test valve clearances ok.
I did them a few years ago and not covered many
miles.

suzuki I wrote down say:
128-172 within spec
limit is 92.4

Now for first time I have done this
with throttle open .

(also bike runs smoothly. not masses of power
but I dont ride it hard !!!!
additionally good run today and zero oil
in areas I sprayed powder.
but yes there is some on rocker cover

what think ?

 

[Gorminrider]

What think?

I think a "compression test" is basically a pump test. It tests the "pump" which are solely pistons and valves and cylinder integrity. Blocking the "inlet" or "outlet" is wrong, because then you are adding a "blockage test" to the "pump test".... Compression tests are done with the throttle wide open. Best on a warmed-up engine.

 

[ukjules]

yes .
results as per pic.

does anyone know what they mean ?

I know the following :

lowest cylinder reading must not be 75% of
highest . mine is well within those limits.

20% increase after adding oil - will burn oil
and prob rings issue
with my stats it is no more tha 15% increase (throttle open)
HOWEVER
Another spec says 3-17% increase the bike would
lose oil and be the rings. mine is right at top end
and using oil.

I cant comprehend my figure as 200psi is superb compression
is it not ?( yet the percentage
difference between were and dry doesnt lie) suggesting rings bad.
What psi do others get on their bikes ?

 

[ukjules]

Compression test conclusion:

Looking online compression can be between 100-200
psi so that is not uncommon.
I think however my issue points to rings.
This is perfectly understandable as I have never
changed them and it was using oil even when I bought
it 10 plus years ago. I have changed the head and gaskets
many times.

So the big oil loss must co e from rings.
The unsightly oil splashes I still dont know
and will continue to look. They must somehow
come from rocker cover ... tensioner...
tacko etc. how on earth the oil gets to te front
from there I'll never know but will find out!

Plan:
About 3 years ago i bought a second engine
off a retired engineer who had totally
reconditioned it (so he says but I believe him)
This has been sat on the garage untouched.
- so I'm gonna take this time to swap engines ,
test new one and leisurely strip down to base
gasket this one.