I want to thank everybody that wrote back on this! I think those of you that said 1200 was correct rpm on a 17A are right,I spent to much time on it with that old 17a engine, I also think 1335 is probably right on a late 48A-75E engine, that thing was wound up!! When we cut it back I did not question my friend that helped me he had been working on Cats 39 years at that time we changed the shims I did not know any different The information I got from all of you about high idle screw and adjusting the rack and torque spring if he told me I’ve forgot, I wonder know in trying to slow it down we didn’t foul up the governor and the power setting I am going to figure this out hopefully bump the RPMs up a little bit. and fix something we screwed up on 30 years ago Again a GREAT bunch of people on this Board THANKYOU. 17afarmer. Mike