Posts: 3472
Location: Elk River, Minnesota | Whoa!!!! Definitely the wrong prop on that boat..
Most motors of that size (mine included) will run a prop that is somewhere between 13-1/4 to 13-1/2 diameter in 17 to 19 pitch. In your case, you are running a tiller rig, so a lower pitch in the 17 range will be in order.
Given your motor tops out at 5500 rpm, you want to shoot for that rpm at top speed with just you and your gear. In the case of what you are running, going to a 13-1/4" diameter in the same pitch you would be gaining about 700 rpms. Going up in pitch to a 17 pitch steel, you would be looking at a drop in about 400 rpm, so you are still up about 300 rpm. If you can find a good OMC raker propeller (3 blade highly cupped, highly raked steel prop that is vented as well) in 13-1/2 x 18 you might be close... It might be a touch high, by about 100 rpm or so, but that can be remedied with an engine height change.
If memory serves me the 618 has its gas tank more to the front? If so, a 4 blade 15 or 16 pitch would be in order within the same diameter.
You will find your boat will be an entirely different animal with a better prop on it.
Steve |
