I've got a 97 Xplorer 400L. When I went to the guys house to buy it He started it and ran it, and it ran really well. Everything seemed to work except the 4x4. I was really pleased with my purchase until the next day when I brought it to a buddies house, as it immediately blew up. Since then its had a full rewire job, all rebuilt engine, brakes, steering bushings, and a few other things. Right now though I've run into an issue. It seems to hit a rev limiter at like 2000 rpm. When I was trying to time it today it seemed like it was definitely a spark related issue rather than fuel, as the light would flick on and off in tune with the engine. It use to work fine, and occasionally it will rev up just fine. I've got a few issues that I'd really appreciate some opinions on. I put a brand new spark plug in, and about an hour later of running time it was fouled again. I put the other new plug in and ran for a minute and it was black. I use AMS oil Dominator in it and I run it at 40:1. Think its the AMS oil, mixture ratio, or something else? It doesn't seem to be burning counter balance oil as it's full. I suspect the needle and seat are possibly worn but if I turn the carb upside down I cannot blow through the gas inlet. Any suggestions? I had another question but I've forgotten. Thanks!