I'm not going to be much help here but I had an 85 HP motor just like yours that acted the same way. I tried about everything from carb rebuilds, spark plugs, fuel pump etc. and never got it off of the starting fluid. I'm pretty sure I tried the manual choke also. It would start the rest of the day after I used starting fluid the first time. The lower unit finally went out on it so I replaced it with a 140 of the same vintage. If I ever try to do anything with this motor I'm going to look into the electric primers as mentioned. How do you install these primers? Where are they wired into?