I have a carter 2150 with a 150cc. I bought it with 15 hours on it. I changed the oil according to the manual and filled it to the top of the hash marks on the dip stick. Then after I started it it has smoked a lot. Oil comes out of the head vent line and gets oil in the air box and it also smokes out of the vent line. I called carter and they said to only fill it have way up the hash marks and that the manual was wrong. I did this and still have the same results. Any help would be appreciated.

did you check it screwed in?Your baffles/packing still have oil in them.

Half way up the marks with out it screwed in is where you want to be. Run it for a bit to burn off the extra oil like Funnyman is talking about. You'll probly be fine after that

Did it smoke at all before you changed the oil? If it was overfilled, it will take a little time to burn the excess out. You will have to thoroughly clean the air box to get all of the oil out too otherwise it will be burning all of that to and cause it to build up extra carbon on the piston and head.

I have cleaned the baffles and airbox and pulled the plug and cleaned it and have run it for about an hour and it still smokes at idle, taking off, running basically all of the time. The oil is about half way with it screwed in. One other thing that I did based on a recommendation was put some lucas oil treatment in it but I have drained and changed to normal.

I hear Nicorete is the way to go.

I wouldn't use it, Nicorette just gums everything up.

Sounds like rings to me. Mine used to have oil coming out of the vent hose. Actually mine still leaks oil out of the valve cover I guess I need a new one. I bought the Big Bore kit and kept it on my shelf until we finally seized that sucker and disintegrated the rings and some of the piston. I wouldnt worry about it just keep an eye out on your oil level and buy the Big Bore kit cause your going to need it. I personally would recommend going with a 180 and go ahead and get the machine work when that time comes.

I tend to agree If your still burning oil you problyneed rings. Do a comp test.

I also did a compression test and it was 115 psi