Props for props

[water dog]

I am looking at props and I am lost what is the differance between a x640 ,and a x642 .I am looking for an upgrade to my auqua jet .I hear maybe x437,x438or x637.The shaft is 3/16 .I s there a designation for the diameter of a prop ?.I had a small 17 foot aluminum boat with a evinrude 40horse and I ran an 18and 22pitch props .The 22 was for speed and the 18 was for power.

[ejp]

x4-- means it has a 1.4 pitch, x6-- means it has a 1.6 pitch. The diameter is the -- so a x640 has a 1.6 pitch and is 40mm in diameter.

[water dog]

Thanks EJP !!!.That clears things up for me .Now what prop size would be good for a 30inch boat weighing in at about 3 1/2 lbs and running a 18 1.3h.p.@ 24,000 r.p.ms.I want speed.

[suck my wake]

Prather Suggested Prop Usage Chart
Inboard Deep Vees
3.5cc - 215 - 220
7.5cc - 230 - 235
11cc - 245 - 250
15cc - 255 - 260 - 265 Outboard Deep Vees
3.5cc - 215 - 220
7.5cc - 230 - 235
11cc - 240 - 245 Outboard Tunnels
3.5cc - 215 - 220
7.5cc - 230 - 235
11cc - 240 - 245
Inboard Outrigger Hydro
3.5cc - 220 - 225 - 230
7.5cc - 240 - 245 - 250
11cc - 255 - 260 - 265
15cc - 265 - 270 Scale Hydro
11cc - 245 - 250 - 255

Large Gas Powered Boats
20.0cc and up - 270 - 275 - 280
Inboard Cats
3.5cc - 220 - 225
7.5cc - 235 - 240
11cc - 255 - 260
15cc - 260 - 265

I hope this will help you out

[Doubledog]

We should try the prop swap that others are doing. The way it works is you post props you have to trade & what you need. No money exchanges hands unless you work a deal out.

Btw, would be good to be posted in the Classifieds or General Discussion.

[Ron Olson]

For the Aqua Jet, try an Octura X-637 or the X-440 2-blade.