My D17 LP started running rough with an intermittent misfire and lack of power after I started it up after sitting all winter.  I thought it was the fuel system and checked everything over but couldn't find a problem, although setting the idle screw richer seemed to help a little. I had just re-filled the LP before parking it for the winter, and thought that might be the problem.

Anyway, I decided I'd better check the electrical and that's when I noticed some white "fuzz" (as Steve at B&B calls it) on the points.  Pulled the distributor and serviced it and re-installed it and va voom. Back to running like it usually does.  Must have been the high humidity at the early part of winter.

Just goes to show as we say about the old Brit cars. "Most carb troubles can be traced to the distributor."LOL