prop time, 18 cc 150 johnson

[Rhody]

Just got back from the test run with the 15x15 prop. Conditions were a little choppy.

4000 rpm 28.8 mph
5000 rpm 35.7 mph
WOT 5400 rpm 39.5 mph

Egg, thanks for the contact and the 90'/60'info. My 150 is a 90' block.

I think I will use it. Only lost 2.5 mph but the engine will be under less stress with a heavy load. 39.5 or 42 mph is too fast under most conditions in an 18' boat (for an old man).

[eggsuckindog]

Just got back from the test run with the 15x15 prop. Conditions were a little choppy.

4000 rpm 28.8 mph
5000 rpm 35.7 mph
WOT 5400 rpm 39.5 mph

Egg, thanks for the contact and the 90'/60'info. My 150 is a 90' block.

I think I will use it. Only lost 2.5 mph but the engine will be under less stress with a heavy load. 39.5 or 42 mph is too fast under most conditions in an 18' boat (for an old man).

Makes them much easier to drive at cruise speed in heaveier seas as its not trying fall off plane all the time. Numbers look good

[2182]

remembered the gps yesterday. 30 mph at 3300rpm, 40 mph at 4600. wouldnt turn more than 4600 yesterday w/ full tank, girlfriend, and heavy cooler on board. definitely going to have to go smaller (prop) but not a bad starting point.

[eggsuckindog]

Check what you have- 17/19 as Mike couldn't remember what he gave you but thats hauling at 3300. You'll lose a little of that going down in size but it will be drivable. I bet its a 19 and I would have thought it would swing one one.

[DonV]

"w/ full tank, girlfriend, and heavy cooler on board."

Justin

Excellent positioning of the word "heavy" in your sentence. A couple spaces to the left and it would not be pretty at your house!! Ya can't be too careful!

[2182]

i know. i get enough eye rolls from her seeing me either on csc or charlestonfishing.com. she weighs all of 115 lbs, cooler probably weighed 75. it amazes me the difference in top end rpm w/ different weights in the boat. went out for a quick trip yesterday and she turned 5150 again (skeleton crew; me and nothing else on board). probably should just use sand bags to simulate weight where it goes for prop tests...

[1Step]

This is interesting.
I have 2002 Johnson 115 on my 1989 18CC and am running a 18 pitch Cyclone 4 blade. I'm getting about 36-37 MPH @ 5400 WOT with 3/4 fuel, another person and typical fishing load.
This past weekend with 3 people total, I was running 26 mph @4100 but it was a solid 2' wind wave so tabs were being used.
I did add the 6" jackplate and the performance/speed seems a little better, but I do get more bow lift.
Can't wait to try it out with a light load, I should hit 40 MPH.
BTW, my neighbor who fished with us this weekend (he has a 21' Seahunt) couldn't believe how nice my little 18 ran and never got him wet

[follybob]

I've been in touch with Skip's Propellers lately and have tried several props and exchanged them. They are on Cross County Road in North Charleston. With my old Crossflow 150 on my 18' and 2 people I am seeing 47 mph GPS and 5500 RPM with OMC 14.75 x 17 pitch Viper. Trading in for 14.25 x 17 pitch Stiletto this week to see what happens. Looking for 5800 and 50+ MPH solo and no load.

[Michael Vezzosi]

Hey! You gotta check out the 13 3/4 prop on Ebay! 15 bucks or something ridiculous. Ends tonight but does not state amount of splines. Sounds like what you need. www.continuouswave.com (Whaler) under Marketplace. Check it out! Part II.

[2182]

rob, thats exactly what i would like to be turning. i spoke w/ brooks oswald (oswald props on JI) and am going to start trying them out this weekend. would like to see 5800 empty boat, 5500 loaded down. also, got transom hatches installed yesterday; the good news is they look amazing, the bad news is i cracked one of the old ones trying to remove the hardware. give me a call when you get back into town and you can come grab them...