Look for an exhaust or fuel leak.
If either occur the engine will start in the water, but it will just
crawl along at wot and never get on plane.
Another possibility is a rag stuck in the exhaust or water box. It
is common for people to forget the had a rag in the exhaust hose,
pipe or cylinder while they were working on their ski.
Another thought is did you replace the gas cap sometime before
the problem occurred? People often replace the gas cap and forget
to remove the gas cap gasket and install it in the new cap. After a
while the new cap allows water into the gas tank, and eventually it
(water) gets trapped inside the carbs.
Bill M.
