So my father-in-law has an older 160 that has progressively gotten harder to start. He cranks and cranks and as he does so, it will fire, but not take off. After cranking for a bit (20 seconds or so), it will finally fire enough to take off. A couple of weekends ago, I decided I would take a look. It has spark and seems to be getting fuel to the carb. I cranked on it for 10 to 20 seconds and checked the plug to see if it was wet. The plug was as drain as a bone. I pulled the carb off and began tearing it down. Didn't notice any major debris. The needle valve has that rubber sealing conical surface. It has a little groove around the diameter of it. I pulled every little part off it I could find. The bowl seems to be full so, I think the fuel pump is working and it is getting gas. My question is maybe to much gas. Is that a potential? If getting to much gas, wouldn't the plug be wet? Like I said, there was no sign of any fuel on the spark plug. I filled the spark plug with gas and stuffed it into the hole. It cranked a little and tried to start. One more thing to add, when it finally decides to run, it runs really rough and has a bit of a miss. Also, he says it burns no oil and seems like it has good compression. Any thoughts as to what it could be?