Merc 9.9 High Revs Going Into Reverse

Joined
Mar 1, 2012
Messages
17
My 2017 Mercury 9.9 has a very high idle in neutral. When slowly putting the gear into forward, it calms down to an idle, which is fine, but if I try to go to reverse from neutral it revs up super high and slams into gear. Does anyone know what may be the cause of this?
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,671
You are way too high in idle RPMs. Should be a (normally) knurled spring loaded adjustment on the throttle linkage arm in the engine. You need the PRMs fast enough to keep the engine from dying when in F gear and the boat moving, yet rotation be slow enough allowing time for the gears to mesh.

The reason R is harder than F is that F gearing interface is different since it includes an "overrun" clutch for times when you cut the throttle, on plane for example, and the water is forcing the prop to turn faster than the engine. R doesn't have that problem so the interconnect is vertical sided cogs and slots so you have to have the RPMs slow enough to give the clutch dog, spring loaded cog time to fall into the slot when passing over it.

675 +- 50 RPM is my current engines spec., in F gear, boat moving.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,342
Does this have remote throttle and gears ? If it does then sounds like it’s related to that.
 
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