I hope you  get  those done too before hay!   lol   its  not that far off now ...

we have a  1655 thats acting like  the 770 you speek of.   And then there was the mechanic that said there is  no  timing marks  on that  particular pump at all... he put it back together  by guess....    YA  its not a good starter at all..   to  aid in the starting  he took off the  heater and replaced the circut with an either kit  ---  that works.