1999 Volvo Penta 5.7 GSI Throttle Issue

[bigernie71]

I had a mechanic do some lower unit work. While he did that, he suggested I should also replace throttle and/or shift cable.
Now the boat idles in neutral at around 700-800 RPM's. Once I throttle above 2000 RPM's and lower back to idle (not neutral), it lowers to about 1000 RPM's. Once I put in neutral, it raises to 2000 RPM's and will not lower to idle RPM and shifts very hard due to the high RPM. If I turn the boat off and start again, it returns to around 800 RPM's. It will drop down to the expected RPM's as long as I dont rev any higher than 2000 RPM's. Unfortunately the mechanic is having some major health issues and will not be able to look at it again. Before I dig in, I wanted to reach out to this community to see if you had any suggestions.

 

[dubs283]

Not properly adjusted throttle cable comes to mind. Needs to be adjusted/set with the throttle closed/idle with slight preload again the throttle arm stud

 

[itsathepete]

Sounds like you need to check throttle and shifter cable settings. There are guides out there, but basically adjust throttle cable as dubs has said and verify that when the shifter is in neutral, the shift cable is adjusted on the outrdrive so that the shift linkage is centered between forward and reverse. And finally, verify that when a gear is engaged, it is fully engaged before the throttle is opened past idle. That's the real quick and dirty

 

[bigernie71]

Much appreciated @dubs283 and @itsathepete. Resetting the RPM's by turning the boat off/on was throwing me off.