The Vaporen's CP is 1643 and HP is 94. Fast move is Thunder Shock, and charge move is Thunder.
2336 CP Vaporen
The Vaporen's CP is 2336 and HP is 198. Fast move is Water Gun, and charge move is Hydro Pump.
Jolteon beats Vaporen
Jolteon beats Vaporen successfully
Even though the HP of Joteon is lower than that of Vaporen, it defeats Vaporen by dodging attacks to save HP. Jolteon's charge move, Thunder, is super effective against Vaporen, so using charge move many times is the best way.