Just found this site while looking for parts for my johnny. I'll make it sweet and brief. Just purchased from original owners son. Sat for about 7 years. Oiled the holes, new plugs, new gas and it pretty much fired off without a lot of trouble. On the water it runs great cold. Seems like when it warms, at higher rpms it will suddenly drop rpms to idle range and struggle to stay running. If I keep the throttle up high it will attempt to kick in off and on and then finally take of but with missing or attempts to low idle problem. When at its worst it does it at low rpms as well. I am rebuilding the carbs as I write but they seem pretty clean.(weird, as they sat for so long) but maybe the owner had them rebuilt in the past. Cant find out, dead, but they looked like thay have been off at least once. I'm wondering if this model has a derate ability if it detects a cooling problem. I did rebuild the water pump already. But I read it has a thermostat type system. Not familiar with it. Thats about as brief as I can make it other to say (what a gas hog) but it sure pushes this 18' cuddy around great. Thanks for any comebacks.