Ive got a bigss vanguard 16 hp horizontal shaft model # 303447, on my chipper. I went to start it up to get the engine warm so I could easily change the oil and it smoked really bad after it got hot. I changed the oil and noticed there was some gas in the oil and knew if had to be the needle was sticking open. btw, this has the top mounted fuel tank. I changed the oil and blew the carb out and replaced the spark plugs but it still smokes bad once its warm. I checked compression and I have 150 lbs on both cylinders. What could cause it to smoke, is there still some gas mixed with the case oil, or could a head gasket be blown? I had it running for about 20 min. off and on. Dutch

color smoke? might want to check the needle in carb, sounds as if the float isn't doing its job. Matter of fact get a rebuild kit and replace all gaskets and O-rings.

Its possible you have alot of gas/oil built up in your muffler and that needs to burn off first. Had that happen on a snapper, the guy thought he needed new rings but he just had about a quart of stale gas sitting in his muffler =P