I have not, but I mean if their sticking closed rather than open, I could see how it would not want to run. I just thought that a more open exhaust flow might be an improvement versus a big valve interfering with exhaust flow from the chamber. Long ago, Suzuki came out with an exhaust limiter in an attempt to improve bottom end performance on their quads, I believe it was the Quadracer 250 and it was actually hurting performance all around unless you removed it from the engine. I was only asking to see if this might be a similar situation, but apparently not. I just obtained this ski, a 96 XP, and so far have not had time to get it running, but I know, (because I checked it myself, without the RAVEs installed) that it has 150lbs psi compression on both cylinders and I think would be a worthwhile project to get running. I'm just trying not to spend anymore than I have to since I only gave $600 for it, a single trailer as well as a double trailer with a running 92 GTX and a recently rebuilt, non-running 94 GTX. So, that is my situation at the moment and I found that I need a stator for the XP today and hopefully not too many other parts to fire this mother up! Thanks again, I know this site is a valuable resource because I have been using it for the last year to repair many a Seadoo.