D-200 hydro pump movement and fluid types

[wheeliefishin 0]

i was getting my dads D200 going again after 15 years....(shiney tank with at least 15 yr old gas......gas wasent that bad???kinda weird seeing as how nowadays it goes bad alot quicker....) the old pump had the splines sheared off when dad used it last... so i went on the quest to find a shaft...got a pump with a good shaft....engine runs like it was new (after i put the coil hot wire where it belonged with the condenser on the left side...makes me wonder what else im gonna run into ...dads are great sometimes....)anyway pump seems to be working was getting ready to prime it up and dad wanted to check to see if the push valve was closed .....closed it and then i gradually moved the lever forward and reverse to prime it once then twice....on the other side over there he decided to open it to see if it made it work faster( i guess thinking to help the fluid pump up faster???).....a bunch of fluid pours out of course....atf fluid.....i know that wasen't right...... so here i am after reading some posts....i am wondering should i really keep the atf like some suggested?????? or put in the mobil 1 10w-30 and a new filter???? mobil 1 should more than make up for the heat issues that would arise...and im all about what's supposed to be in it....taking the time to learn and not rushing or "seeing what this will do." he he usually the FSM is my best friend with all my vehicles and machinery...my questions are... 1. should i keep the ATF or axe it 2. could not greasing the pump shaft splines with some moly have caused it to shear off splines???? it seems like maybe some engine mount bolts loosened and got outta alignment would be a more likely scenario...after motor work or something...or maybe some atf fluid causing a heat lock-up????he he...the new old pump shaft is greased..... I am so anxious to get her up and 110% (Hearing it run was the best sound and feeling i've had in a while....dad looked as happy as as i was when i saw the only problem with my coil was the points wire being over with the key side and not with the condenser) It was the best feeling to remember ...i was just a little guy sitting on my dad's new pride and joy and him letting me mow with it....( i was terrified i would mess it up for a second some how but that didnt last long) it was the best...