Had the 4HP Myrick on the trailer for the last show we attended. Lit the tube and after a bit and it started and ran flawlessly, as usual. I flipped the oiler on and off to my easy chair. About ten minutes into it I thought it was hitting a bit more often than usual and by the time I was certain of it and got over to it, it was both heavily laboring, and clunking (aka heavy knock) It stopped with a thud when I shut the valve off.
At the shop next day we took the top end down and found nothing wrong except it was dry inside and some very light scuffing. What the ???
oiler was set same as has been for two years??? Had to re-enact to weekend to figure it out ( I think?) Two things happened. one is cooler fall weather. I had set the oiler when it was 95 in the shade and it wasnt dripping very fast. Other perhaps larger thing was the way I had the engine on the trailer and how we were parked caused the oiler to be downhill from horizontal and between of slow dripping and having to fill the pipe before any got to the cylinder,,,
Good thing is no apparent damage. We reassembled it with plenty of oil, set the oiler up a few notches and it ran for an hour in the shop just like usual. I like free lessons, Pheew!
Double check your oiler rates when the weather cools down guys! Especially if you have some horizontal runs on the piping.