The Omni uses a sidedraft carb which is different from the 800's carb.Make sure all the venturis are not sticking.You can use a carb cleaner spray to clean it.Also use a fuel system cleaner for extended cleaning.
If you consider a rebuild get it done at someone who is well versed with carbs.There are many small screws and settings.
If you consider a rebuild get it done at someone who is well versed with carbs.There are many small screws and settings.