soft valves in a KLE

Hi Folks, Have any of you experianced  hassels with clearances on your inlet valves getting less &less over +_  5000 km . Have had the bike for 14000 k,s ,& have to adjust clearences  far to often . Starts off with erratic starting ,and gets worse&worse . I got so pissed off with reliability issues i bought a BM Dakar,    Mrs P started riding the KLE and is happy , but sh**%$t happens & voltage regulator popped &fried the battery . A little MAY DAY ride ended up with expensive noises from the motor .& atrailer trip home . Opened the motor on saturday after a compression test and found the inlet valve clearences nill slacked off adjusters & RHS cylinder  compression was back to1300 kpa LHS was 800 .      Pulled the head&sent it to motor eng. pal tocheck . He phones & says the inlet valves are paper thin and should be replaced.........                                                                                                                                        why would they flatten out like that,its really such agreat bike to ride ,but  we cant trust it . would appreciate anyfeed back