mackr1989 Posted January 30, 2016 Share Posted January 30, 2016 our 89 rd690sx ten wheeler dump has a 300 with 8 speed mack trans. the rpms will only go as high as 1800. someone told me the 690 series was a municipal spec truck and the engine it has was designed to run vacuums or pumps and things like that. our 88 is an r688 and the rpms go as high as 2200. is what i was told about our 89 690 true? Quote Link to comment https://www.bigmacktrucks.com/topic/43781-300-econodyne-rpms-wont-go-beyond-1800/ Share on other sites More sharing options...
j hancock Posted January 30, 2016 Share Posted January 30, 2016 The 690 has a 1750 rpm engine and the 688 is a 2100 rpm engine. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/43781-300-econodyne-rpms-wont-go-beyond-1800/#findComment-322290 Share on other sites More sharing options...
GreenGiant2 Posted January 30, 2016 Share Posted January 30, 2016 300 L slower turning engine? Quote We the unwilling, Lead by the unqualified, are doing the impossible, for the ungrateful. Link to comment https://www.bigmacktrucks.com/topic/43781-300-econodyne-rpms-wont-go-beyond-1800/#findComment-322329 Share on other sites More sharing options...
57 bcr Posted February 1, 2016 Share Posted February 1, 2016 The EM6-300L that was in my '90 RD690S, would run 2100 from the day I picked it up,new. Al Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment https://www.bigmacktrucks.com/topic/43781-300-econodyne-rpms-wont-go-beyond-1800/#findComment-322536 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.