I have a OMC 140HP -85 outboard that has done faithful service. When I jerk
the flywheel back and forth I notice a small radialplay with a "clonk"
sound.

Is this normal or are the main bearings defect?? It runs OK with no
knocking sounds.

/ Ulf

Sweden

Hi again, perhaps I should be more specific. It is the SIDEWAYS movement. I
know that some up and down movement is normal.

/ Ulf

Sweden

"Ulf B" wrote in message
...
Hi again, perhaps I should be more specific. It is the SIDEWAYS movement.
I
know that some up and down movement is normal.


With this clarification I am now more confused.

There are three possible motions that could have movement.

There is a vertical (assuming the engine is in the normal operating
position, with the flywheel on top. This would normally be referred to as
"endplay". There should always be some, but an excessive amount indicates a
worn thrust surface. This can be a real bad thing on a car with a standard
transmission as it can really mess up the clutch action, it might not be a
significant issue to an outboard as long as it didn't transfer engine weight
down the driveshaft.

There could be a side to side motion, which would indicate a severely worn
main bearing. If you can detect any significant amount of side play then I
would say that you have a problem.

You might also be talking about a rotational play, that you rotate the
engine clockwise/counter clockwise and there is a small rotation and a
CLUNK. A small amount of this would be normal and it wouldn't surprise me
for it to increase as the engine got older. There could be a little slop
where the driveshaft to the lower unit engages the powerhead, and then a
little more in the gear case in the lower unit. There could also be a bit
of a clunck coming from the water pump which would be on the drive shaft.

If this is a four cycle outboard then you could have a fairly significant
amount of backlash from the cam and valve mechanics.

I suspect that you don't have a problem, that the motion is normal.

Rod McInnis

"Ulf B" wrote in message
...
I have a OMC 140HP -85 outboard that has done faithful service. When I
jerk
the flywheel back and forth I notice a small radialplay with a "clonk"
sound.

Is this normal or are the main bearings defect?? It runs OK with no
knocking sounds.

/ Ulf

Sweden


I don't know much about it...but that doesn't sound good. If you start
the engine -- does the flywheel move in a circle or is it somewhat
elliptical. Maybe putting a white mark on it would help you tell??

Or maybe the centrifugal forces keep it centered when it is rotating.

??

"Rod McInnis" wrote...

There could be a side to side motion, which would indicate a severely worn
main bearing. If you can detect any significant amount of side play then I
would say that you have a problem.


Yes I do believe I have.......... :-)

I talked to a marine shop today and the told me:

You need major overhaul.

This is expensive and really not worth on a 20 year old engine.

Buy a new one $$$$$$$ well the new Yamaha 4-strokes looks
promising..............

/ Ulf
Sweden