We've been putting a 115 hp Evinrude outboard back
together for a little over a year now. It took some time,
but we finally got all the pistons turning easily and
smoothly. We mounted the block back and attached
it to the lower unit, and then put the heads on. I don't
remember when the last time was we tried to move
the pistons, but at some point we did something wrong.
There's something solid stopping the system somewhere
and it only lets us turn the flywheel about 1/4 turn or less
in both directions before something clonks into something
else and stops its travel. Could we have put a head on
wrong so it's catching a piston, or is it likely to be something
in the lower unit like a spline lined up wrong, or what?

Thanks for any help!

hanuman@dot. wrote:
We've been putting a 115 hp Evinrude outboard back
together for a little over a year now. It took some time,
but we finally got all the pistons turning easily and
smoothly. We mounted the block back and attached
it to the lower unit, and then put the heads on. I don't
remember when the last time was we tried to move
the pistons, but at some point we did something wrong.
There's something solid stopping the system somewhere
and it only lets us turn the flywheel about 1/4 turn or less
in both directions before something clonks into something
else and stops its travel. Could we have put a head on
wrong so it's catching a piston, or is it likely to be something
in the lower unit like a spline lined up wrong, or what?

Thanks for any help!


A, Drop the lower unit and see if the crank moves properly

If it does, bingo.

B. Might you have put a key in improperly?

I wonder if you replaced your piston rings? An oversized ring will do it
once the gap closes completely. Or maybe, In two stroke engines, The rings
have to be positioned properly.

hanuman@dot. wrote in message
...
We've been putting a 115 hp Evinrude outboard back
together for a little over a year now. It took some time,
but we finally got all the pistons turning easily and
smoothly. We mounted the block back and attached
it to the lower unit, and then put the heads on. I don't
remember when the last time was we tried to move
the pistons, but at some point we did something wrong.
There's something solid stopping the system somewhere
and it only lets us turn the flywheel about 1/4 turn or less
in both directions before something clonks into something
else and stops its travel. Could we have put a head on
wrong so it's catching a piston, or is it likely to be something
in the lower unit like a spline lined up wrong, or what?

Thanks for any help!

"mscres" wrote in message
...
I wonder if you replaced your piston rings? An oversized ring will do
it once the gap closes completely. Or maybe, In two stroke engines, The
rings have to be positioned properly.

hanuman@dot. wrote in message
...
We've been putting a 115 hp Evinrude outboard back
together for a little over a year now. It took some time,
but we finally got all the pistons turning easily and
smoothly. We mounted the block back and attached
it to the lower unit, and then put the heads on. I don't
remember when the last time was we tried to move
the pistons, but at some point we did something wrong.
There's something solid stopping the system somewhere
and it only lets us turn the flywheel about 1/4 turn or less
in both directions before something clonks into something
else and stops its travel. Could we have put a head on
wrong so it's catching a piston, or is it likely to be something
in the lower unit like a spline lined up wrong, or what?

Thanks for any help!




Yours is a very good suggestion. The rings must be aligned properly with
the pin in the ring land at the gap in the ring to keep it from moving
around in the land and where the end can get caught in the exhaust port.
Some amateurs don't realize this and they install the rings and crush
the pin into the piston with the end gap of the rings in the wrong
place.

Attaboy!

Wilbur Hubbard