L150XTRT runs great on land but not water!

[TownsendsFJR1300]

if OP would have pressurized the cylinder with compressed air like doing a leak down test would have said if it was a head gasket leaking into another cylinder and coming out the other plug hole.
too late now

Yepper, I posted that, ^^^, yesterday (post #30).

Time will tell, nothing $ can't fix!


Worse case scenario, as noted above, disassemble and punch out that cylinder.

A leak down test, after assembly (if compression is still low), would help decide if the second low cylinder needs attention as well..



Fingers crossed for the op!


.

[JDWOODBURN33]

Took a measurement of the cylinder seem to be close. Batteries are dead so I could get digital reading.
Screenshot_20200702-193324_Gallery.jpg
As far as I can think of testing wise, I'm ready to pit it back together and see if I raised the compression at all.

[panasonic]

Took a measurement of the cylinder seem to be close. Batteries are dead so I could get digital reading.
Screenshot_20200702-193324_Gallery.jpg
As far as I can think of testing wise, I'm ready to pit it back together and see if I raised the compression at all.

Sorry sir, but you cannot measure cylinder bores like that. You will need a set of telescoping snap guages and a working set of good vernier calipers, or better, a micrometer to measure the snap gage. A machine shop will probably use a proper bore Guage. Close is only good in horse shoes not cylinder bores.

Anyway nothing to lose putting it back together and giving it a try. Maybe your rings were stuck. Did you try soaking them to free them up.?

Best of luck.