Pontoon Boat & Deck Boat Forum

I have a 24ft StarCraft with a mercury 90 2 stroke. Other than idle issues the engine has run really well for the last 5 years.
It always ran smooth at higher rpms. This year, at full throttle, it would cut out and surge at higher rpms. The mechanic said everything checked out, but he took the cowl off and ran the boat and when trimmed down, the cowl is filling up with water and covering the lowest cylinder spark plug. The boat never surged before. I did check the pontoons for water, thinking it was riding lower in the water. Has anyone ever had this issue before? Any thoughts would be appreciated.
Thanks

Are you sure water is spraying in and your pee tube (ha) isn't broke letting all that water enter the motor vowel.

I had the same issue, but mine was self inflicted. My back grilling platform was shooting water against the motor....after a while the rpm would drop at full speed. I fixed the spray and now it's perfect.