rumbles

Hello I'm looking at a 2014 Sherco ST 300, I have read scattered reports on these bikes having some water pump issues. The owner who seems meticulous and writes very poor English responded with and I quote " I put spacer Jitsie for more cooling liquid and water pump aluminium turbine for best performance " when I asked him if he had any water pump issues. The bike looks brand new and the hour metre registers 5.5 hours. Can anyone give more information on this issue?