Last time out last year begain to run slow(about 10mph) so over winter i cleaned raves,checked compression, changed plugs, drained and added new oil and gas, checked injectors took it out put in the water ran great for about 30 min then started to surge and slow down would only go about 10mph (3100 rpm) back to dock put it on trailer and it revs up and sounds good but wont in water. Any help would be greatly appreciated.