Itinerant Air-Cooled

Hey gang. '78 Westy 2l FI. My Westy has been sitting for nearly a year (I know, shame on me) ... I'd starter her quite regularly during this period though....

Took her on a short trip this weekend and she progressively ran worse. Got home and was starting a full tune up and decided to check compression. #3 topped out at 30, the others between 90 and 100.

Is there anything I should try to boost/restore compression on #3? Thanks!

Hi there,

I'm going to ASSUME your '78 bus has hydraulic lifters. Did you get any clattering at startup? How about a 30+ mile drive with clean oil to ensure the lifters have pumped up, followed by a valve adjustment. If I don't have a valve adjustment on recent memory, I don't even get the compression tester out.

Starting regularly during storage periods won't help the lifter situation since idling without a long/hot/hard run won't burn the moisture and condensation out of the oil.

Did your "full tune up" include valves?

Robbie

Worst case is you may have dropped a valve seat on #3, but it seems unlikely. You may be able to peer down the #3 spark plug hole and see if a valve is being blocked open by a dislodged seat. In this scenario the compression would be 0, though, so probably not the case.

More likely that the valve stems on #3 have varnish crudding them up, causing them to stick and prevent the valve from seating fully.

Try one of the popular snake-oil formulations like Marvel Mystery Oil or Seafoam to clean out your engine and see if it frees things up. Short-term only. Be prepared to do a couple of sacrificial oil changes with inexpensive oil before you commit to some good stuff for long-term.

Best of luck.