Hi Guys ....I was flying my 100-50 bird this am, and on landing approach, the engine quit, just over the threshold. The wind was blowing my hair off, but luckily the old 100/50 suffered no damage. The reason for this post is I am looking for any possible information. The engine is an OS FS-91. When i refueled and went to restart, there was no compression. Removed the valve cover and found the intake valve spring broken. I realize things break, but this is the 2nd time I have had valve springs bust on the FS-91. I have three of these engines, so i have a good batting average for valve spring breakage. Does anyone have any such experiences with this engine, or am I treating it mean somehow?

Bruce