Hello I have a case 448 with a onan pc18g engine. It runs fine with it brand new nikki carb, but there is a noticable ticking noise in the engine. I know its not a knock as it is quiet but noticable. There is no lose of power or engine problems at all. In fact if you were wearing headphones you would not know the ticking existed. The engine tick is very rythmic and when you rev up the engine the ticking rate speeds up as well. I changed the oil with 1 quart of sae10w30 and the dipstick reads perfectly full. All help is very appriciated. Thanks guys for supporting this great forum and have a great rest of your day! I can send pictures if wanted of the 448 later.