GS550E 1980 engine leak Crankcase or where ?

[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.

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[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 ?
20201106_134058_resize_19.jpg

[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.

[tatu]

That amount of oil, are you sure it isn't valve stem seals?, If you're going to open and do the gaskets refit with viton kind, ebay. I get mine from a supplier in the US, he does one that looks very similar to OEM with a metal sleeve all around. You can get from SPS (suzuki Performance Spares, (Nick Pepper) they do the Viton ones with a wire spring that locates. Still very good and won't fail. I used those on my ELR Kawasaki and are perfect.

[ukjules]

I tend to agree.
when I get to this engine it has to be as you say
oem gaskets , stem seals , check valves,
clearances .....

this is my favourite bike and madly
the one that lacks detailed documentation.
as it keeps going forever seemingly I
have not treated it as a project.
My other bikes I have all details
in a folder.

New folder and docs now sorted.
I'll leave this engine and try the other
one as it is meant to be perfect.
That is cheapest way forward and then at
leisure I can do this one as a spare.

[ukjules]

I must say I appreciate as always the expert advice
but am surprised you missed the one thing....

ie.

- fit that spare engine fully reconditioned
by a engineering expert you have sat in the back
of your garage sat in test cradle (inc in price)...

20201108_104655_resize_48.jpg

The project starts this week.
Can you believe not a single stripped thread.
A straight swap but need to swap electric ignition,
cam cover gasket and new breather hose , oil , filter
and that's it.

[ukjules]

Engine out . easy pace at 3 hours.
Not gonna rush so clean up threads etc and new
engine in tomorrow.

issues :
- cant remember how I put and config the
electric ignition (newtronic).
-3 bond arrived and need valve cover gasket.
gonna go for cheapo with 3 bond for a test.
- how to remove side engine case circular stickers.

20201112_124458_resize_28.jpg

[ukjules]

Swapping bits from.old engine.
New 2nd recon engine for sure was done by a skilled
obsessional retired engineer as it is quality .
The exhaust bolts are studs and not a stripped thread
about. I fell on my feet when I bought this.

My old one i can see my own neglect for the sake
of my other 3 bikes. No more the GS gets the full treatment now.

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