Hello. I have a Johnson 28 spl. Ive been reading around the site before posting and it sounds like I may be fine but it doesn't seem like it to me. I know you get asked this a lot and I apologize, so I tried to put a pic in so you can see. Is this what your saying is normal? I did check the lower unit and the oil looks good and not leaking. The person I bought the boat from only fished an idle only lake for 2 yrs and never opened the engine up. When I ran the engine in a tub of water I would get little black particles, like crust. From what I'm reading that's carbon build up and normal. This is my 1st boat so you can see why I'm so concerned. Thank you