Low top end speed 4.3lx?

Dillle209

Cadet
Joined
Jun 4, 2018
Messages
12
hey so i have a 1996 Larson 174 sei with a 4.3lx with 400 hours with a 19 prop and i can only reach about 35 at 4200 rpm i can go higher on rpms i just don’t like to wot .is this a normal speed at such a high rpm ?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Your motor can do WOT and this is the only way to know if your propped correctly. You should be able to get between 4400-4800 rpm
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
you need to test WOT with the throttle mashed against the stops.

this is normal and you can run the motor there for a short period of time to test your top speed.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
What gear ratio does your engine have?
You have to prop it so it runs within its recommended rpm range at WOT, not because you want to go run a certain RPM at a certain MPH.
A 17 ft boat with a 4.3 should see around 45-48 mph at WOT
 
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