Jetski don’t want to speed up

[Tbierry]

Hello, I just bought a 2 stroke bombardier and the other owner just put 91 in the tank but not mix up. I tried the jetski but when I put more speed the engine don’t want to put all the speed and go back to idle. I want to know if it’s the beacuse he don’t mix up or not. Thank you !

 

[POPPS]

If there was no oil in the gas, then the pistons are probably seized,
Pull the plugs, do a compression test, and go from there.