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Evinrude 90 torque specs

jellyfish84

New member
just wondering if anyone could

just wondering if anyone could tell the the torque rating of a 1990 evinrude 90. i can seem to find it anywhere
cheers
 
"Eric, what torque numbers are

"Eric, what torque numbers are you looking for?

How much torque the engine puts out? or the torque specs for various fasteners??"
 
"Eric,

HP = (Torque x R


"Eric,

HP = (Torque x RPM) divided by 5252

Lets say your motor is rate at 90 HP @ 5500 RPM. Working back from the above formula the torque would be 85.5 lb ft of torque. Do the math. 85.5 x 5500 = 470250. Divide that by 5252 and you get 89.54 HP. The discrepancy is that I am only carrying out to two decimal places. Now if you want to know specifically what you motor is capable of you would have to put it on a dynamometer. If I have made a mistake here I'm sure I will be corrected."
 
"Hey, Greg and I just had a hu

"Hey, Greg and I just had a huge conversation about this very subject.

Here's the numbers my software spits out -

Your 90 SHP Merc produces about 93 Brake Horse Power (BHP) which as Allan states produces approx. 89 foot pounds of torque at the crankshaft @ 5500 rpms.

After passing through the gearbox (lower unit) and the bearings on the propshaft that is converted into the "Propeller Torque".

Depending on the gear ratio, that will produce different numbers at the prop.

I'm trying to remember the ratio's for the 90 off the top of my head, but not certain. However, typical Merc gears (built by Yamaha) would be (roughly):

1.8 producing 161 ft/lbs
2.0 producing 172 ft/lbs and,
2.33 producing 201 ft/lbs at the prop.

The 2.33 gears are standard on the smaller horsepower bigfoot series and were also optional a number of years back, marketed as "high altitude" gears for the higher horsepower motors.

Actually though, it is the measured "thrust" from the prop that moves the boat - this does not exactly equate to horsepower or torque but those are terms that most can understand.."
 
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