Mark, that trick of using two cable ties as a valve spring compressor for Briggs engines was introduced to Outdoorking by Joe Carroll several years ago, and has been recommended here since then. I've never found any need for a spring compressor on OHV mower engines, since low speed engines have very weak springs, and you can easily use your fingers. However side valve engines are another story, because of limited space, and even most commercial spring compressors won't fit in there. A simple forked lever can work pretty well, especially for the stronger springs found in side valve car engines, where the use of fingers or cable ties is not a realistic option.
