Self Service

[Nikon Samurai]

I have a 1999 Johnson 50 hp outboard model J50PLEEA. I purchased this boat last year and have used it at least 2 days a week. This motor has been through a lot. The only trouble is has given me is when i put the choke up to start sometimes it will take off. Any ideas on how to fix this? I have checked with the previous owners and the motor has never been serviced. I've replaced the spark plugs twice but that's it. The motor will not idle so i'm guessing based on what I?ve read i have to rebuild the carburetor. I purchased this kit from Iboats for this motor. Mallory Carb Kit 9-37107. It says up to 1997 but i read the model was in production for 7 years before 1999 so i'm hoping this is the right kit. If anyone knows the correct answer please let me know. Also, i'm guessing it's past time to grease the lower unit. Do i need to remove the existing grease or can i simply use the grease gun on the gun connection between the lower unit and the engine? I would have the motor serviced professionally but after checking prices and getting quotes for $500 and up plus parts, it's not in the budget right now. I did all the electrical with great success so now with your help i'm going to try the motor. I purchased the service manual, it should be here any day. The last prevention step i need advice on is the hydraulics. There is rust on one of the two lifts. Should i remove the rust with muriatic acid and put rustolium paint over it? Your help would be a blessing in regards to the above questions. Thank you for your time.