Depending on the motor you can use Max Rules. They have a pretty good database for years and hp info.
That is a 1956, 30HP Johnson motor.
i have a 21ft sunbrid walk around boat with a 175 outboard motor i would like to know what size propeller should i use
OD281588
175/150
A suzuki outboard motor may cost anywhere in the area of 2000-4000. This price depends on the size, age, and horsepower of the motor. Also, the condition if used is a factor.
does anyone no the size,and year of this motor... here is thr serial # K0131fcucf1157374
100 aph
A Johnson outboard, model 6R-74C, would be a 1974 year model, 6 hp.
250 cc
appears to be 250
In general it is determined by liters or cubic inches.
It's a Chevy 5.0L - 305c.i.