9.9 evenrude sluggish under load

richlee3216

Recruit
Joined
Jul 26, 2010
Messages
5
Hello, I have a late 80's model 9.9 evenrude outboard. Runs really good in a barrel but when on the boat, it's real sluggish and won't push very fast. I cleaned the carb and the plugs. suggestions?
 

tomhath

Master Chief Petty Officer
Joined
Dec 5, 2007
Messages
814
Re: 9.9 evenrude sluggish under load

What boat? How much weight? What do you mean by "very fast"?

I have a Johnson 9.9 that pushes a 14' aluminum semi-vee hull at around 16 mph with just me in it. Not blazing fast, but it planes and gets me across the lake.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 9.9 evenrude sluggish under load

Do a cyl drop test on it to make sure it's running on both cyl's.
 

Hahn007

Cadet
Joined
May 28, 2013
Messages
21
Re: 9.9 evenrude sluggish under load

I have seen this cyl drop test recommended on many many posts. I thought unplugging a plug wire with engine running/cranking could cause damage to the coils or power pack becauase the coils do not have a path to ground on the high voltage side......... Please advise....
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 9.9 evenrude sluggish under load

It won't hurt anything if you have the plug wire off just long enough to see if the cylinder is firing or not.
 
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