Went to a friends house yesterday to fell a 34" diameter White Oak. After seeing and hearing my 390XP run, he asked me if I could do his MS310. I fabricated a new part for the original port cover. I used 1/2 " inside dia. conduit for the pipes. Retuned & tested it in some oak and maple. He is going to be really happy. Runs much stronger now. Here are the results.