The lifters on my 85 1.9 Westy seem to take longer to pump up lately. The chatter/banging used to go away after about 10-15 min of driving but now takes about an hour or more of around town driving to quiet down. I only drive it  during the summer on camping trips or occasionally  around town just to run it between trips and it is stored in winter. I use 20/50 oil with a shot of MMO. Is this slow pump up doing anything serious to the valves or drive train? Thanks for any advice.
Spencer