Problems with throttles

[BRitter1]

Hopefully I will get the terminology correct. I have a 2001 4600 SCB. Having a bit of trouble with the throttles on the diesel. I found that when I throttled back , I could not get rpm below 1000 or so.
It was suggested I pump the throttle a number of times to build up pressure. I understand that these are pneumatic controls (?) That worked and would last several weeks, now I have had to stop after an hour or so and pump the throttles again. I assume a leak somewhere. Any suggestions where I should look for leak, or any suggestions what to do. I will have marina do the work, but would sort of like to know what I am talking about when meeting with them



Thanks for any input

[PJHoffnet]

It's certainly dependent on the system you have - on my 1999 4100 SCA (twin Cummins 6BTA 5.9 M3 330HP) I have a hynautics system that basically consists of a pressurized reservoir that transfer the motion of the throttle to motion of the fuel control element on the engine. Things to check (if you have the same type of system) is pressure and level of fluid in the reservoir and binding in the linkages themselves. Fluid leaks along the lines, or pressure loss in the reservoir tank could be a problem.