Re: what can i use to replace old throttle on 64 evinrude.
Check eBay. Stuff like this crops up now and then. Evinrudes used pushbuttons for manual shifting, separate from the throttle. Johnsons used a single lever throttle with the shift switch built into the movement like the newer setups. Either control will work on either motor, so do a search for both (keywords evinrude remote control and johnson remote control). I'm afraid that nothing modern will work for you and replacement shift switches are awfully hard to find and forbiddingly expensive if you do.