View Full Version : Higher pitch prop = idle adjustment?
EricCO
07-10-2001, 11:29 AM
I went from a 15 pitch prop to a 17 pitch prop on my Merc 115. The idle seems to be at about 800 rpms and dies sometimes.
Do I need to adjust the idle setting since I went up in pitch?
miksup
07-10-2001, 12:42 PM
Since the prop is not spinning at idle, unless of course in gear, the prop has absolutely no bearing at all on your engines idle RPM's. Must be a coincidence. Is that 800 revs in gear or out of gear. 800 out of gear sounds about right and drops to about 650-700 in gear. If it's 800 in gear than maybe a slight tweek down to 650-700 might be in order.
EricCO
07-10-2001, 12:50 PM
800 in gear
A higher prop pitch will put a slightly higher load on the engine at idle - but not very much.
I suspect that the engine dying at idle, with the engine in gear, is more of a conincedence than any thing else.
To verify this - put the other prop back on and see if the idle changes.
My guess is that the reason that the idle is changing is simply weather and or fuel related. Set the idle up a tad and you will be fine.
Take care
REW