What should the Idle RPM Be

cat toon

Seaman
Joined
Sep 20, 2010
Messages
61
I think my idle speed is to low on mt 1987 70 horse Johnson motor what should the idle speed be.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: What should the Idle RPM Be

725 +- 25 RPM in gear with the boat in the water.
 

cat toon

Seaman
Joined
Sep 20, 2010
Messages
61
Re: What should the Idle RPM Be

725 +- 25 RPM in gear with the boat in the water.

I do not understand,when you put the motor in gear the you give it gas also then it is not at an Idle,I always thought at and idle is with no gas except what the carp normally add without the trottle engagued.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: What should the Idle RPM Be

well you didnt say what kind of controls you have...( could be a tiller even!!)

but on a single lever control once the throttle is moved to just fully engage forward...thats idle in gear!

and you need the back pressure of the motor in the water.


engaging the gears naturally add resistance.... but this is what idle in gear is....with the "drain" of the drive shaft turning a prop....


thats how i thought it was

bob
 

boobie

Supreme Mariner
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Nov 5, 2009
Messages
20,826
Re: What should the Idle RPM Be

Cat, listen to what Bob said.................
 

cat toon

Seaman
Joined
Sep 20, 2010
Messages
61
Re: What should the Idle RPM Be

ok,I got it now,My 70 horse is about 950 without being in gear is that to low may stall out when put in gear,I just put that motor on my pontoon and have NOT test driven it yet.

Thank you very much for setting me straight.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: What should the Idle RPM Be

make sure the motor is warmed up prior to setting idle, it might just fall perfect where you want it!!!(750 rpm)

bob
 
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