Speed Issue - Runs fine to 20 then plains goes to 35 boggs down to 20 and stays there, must restart to get to 35 then repeats

[jgfseadoo]

2001 Sea-doo Bombadier GTI - Jet ski goes to 20 then slowly plains then revs up to 30-35 when all of the sudden boggs down back to 20 and stays there, must restart the ski again and the whole procedure continues to repeat...not sure why it just will not stay around 30 without suddenly going back to 15-20 and staying there? Why would shutting the engine off and restarting to again go back up to 30-35 before all repeats again?
Thank you for any help or ideas.
There is no blockage, gates are clear, prop is clear, new spark plugs installed

 

[mikidymac]

Starving for fuel and if you keep running it you will ruin the engine.
Start with carbs and complete fuel system service. For carbs follow the sticky and only use Genuine Mikuni parts.

 

[jgfseadoo]

Starving for fuel and if you keep running it you will ruin the engine.
Start with carbs and complete fuel system service. For carbs follow the sticky and only use Genuine Mikuni parts.

Just got a call from the maintenance tech at shop where it is at ... They serviced all the carbs, serviced all fuel system, put a new seal in the exaust system... one side of the engine shows a lower compression than 140... like 110... tech then took it out for a test ride and it still is doing the same... goes to 35 bogs down to 20 and can't go higher...turn of the engine and then can go again to 35 then goes back down to 15-20... $350 so far in fees... Any other thoughts of what it can be? It is still right now with tech.