Best Prop Size For Johnson 140 4-Stroke

[nikogto]

Hello all. I've got a 2004 Godfrey Aqua Patio. 24 foot tritoon with a Johnson 140 4-stroke, the current prop is a 14x17p. WOT range for this motor is 5500-6200, I'm only hitting about 5400 max weather is't just me or the whole family (5 of us). Speed on calm water is about 25-27mph max, sometimes it will hit close to 30. I was hoping someone would have the same set-up as me. I was told to try a 13 3/4 x 15p. We've had the boat a couple years with this prop, but from what I've been seeing, this boat and motor combo should be well over 30mph. Motor is tip top running shape, toons are clean. Thanks for any info/help in this matter. Nick

 

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

Nick, I have the suzuki 140 same engine as yours on a 27 ft Harris Crown. The Boat came with a 14x18p stainless oem prop. top speed 25 rpm 5200... switched to a solas 4 blade 17 pitch.. top speed 25 rpm 5400... switched to a 15 pitch 4 blade rpm 5600-5700 top speed 25... know i'm thinking 13 pitch 3 blade Turning Point by hustler. to get rpms up to 6000 lightly loaded. 6-8 people have little effect on performance but when I put 12-17 the engine works way to hard. The problem is prop slip.. I cant find a prop that bites the water and have less than 20% slip. Nutinbitin

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Well that 12" is way too small in diameter. I think you'd be best trying the 13 3/4 or 14" by 15p prop. I'm trying to get one here soon. Sounds like your in the same boat as me. Ha Ha ha

 

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

My bad the prop is a three blade 14" dia 18 pitch. The biggest problem I have is when I have 12-16 people in the boat and chugging along at 20 mph the prop loses its bite and starts to rev higher. Would like to find a prop with bow lift and high bite

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Well, Godfrey just got back to me on stock prop size, they say a 13 1/4x 17p. I've gotten the 13 1/2x 17p off turning point props website and did'nt notice a differance, more blowout from a dead stop, you could not feel any thrust. This is such a pain in the *****. It's not cheap to get the right performing prop

 

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

Try going to this website and plugging in the info you have...

http://go-fast.com/Prop_Slip_Calculator.htm

It will tell you how much slip you have. I'm going to try a lower pitch prop until I get to 6000 rpm with just me and the dog in the boat.

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

I've gone to turning point props website and used the calculator and Dave's Discount props calculator, they don't match. Anyone else noticed this? Which site do you use??????

 

[Silvertip]

Re: Best Prop Size For Johnson 140 4-Stroke

What you should be shopping for is a "pontoon" specific prop which are affectionately called "elephant ear" props because the blades are very large and more rounded than props for planing hulls. They have an advantage when in reverse so they work well in docking manuevers. I would guess you need something in the order of a four-blade in the 15P range. I don't get involved with pontoons in that HP range so I can't make any recommendations.

 

[VaGent]

Re: Best Prop Size For Johnson 140 4-Stroke

What you should be shopping for is a "pontoon" specific prop which are affectionately called "elephant ear" props because the blades are very large and more rounded than props for planing hulls. They have an advantage when in reverse so they work well in docking manuevers. I would guess you need something in the order of a four-blade in the 15P range. I don't get involved with pontoons in that HP range so I can't make any recommendations.

Could you recommend an elephant ear prop for a Johnson 70 hp engine that's mounted on a 24 ft JC pontoon? I'm being told in my area to just stick with the 3 blade prop. I'm using a 13-3/4X15 3 blade prop now.

 

[hodginsmn]

Re: Best Prop Size For Johnson 140 4-Stroke

I have a 27' triple tube with a 140 Johnson and have had it real close to 30 mph just by myself, on a calm lake with the wind at my back! I am not sure of the prop but will check when I get it out of storage this weekend.

I have two props with different specs. and had them both on last season and did not notice any difference in performance.

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

what rpm's are you turning wot?

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

I have a 27' triple tube with a 140 Johnson and have had it real close to 30 mph just by myself, on a calm lake with the wind at my back! I am not sure of the prop but will check when I get it out of storage this weekend.

I have two props with different specs. and had them both on last season and did not notice any difference in performance.

Ever get it out of the water? What are you turning for WOT rpm's?

 

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

I broke down and bought a 14 inch 13 pitch three blade prop. I will test it out and post the info in a week or so. I now have a 14"-18p 3blade, a 13-3/4"17p 4 blade, a 13-3/4" 15p 4 blade, and now a 14" 13p 3 blade. I'm hoping for 6000 rpm wide open lightly loaded. nutinbitin

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Nick, I have the suzuki 140 same engine as yours on a 27 ft Harris Crown. The Boat came with a 14x18p stainless oem prop. top speed 25 rpm 5200... switched to a solas 4 blade 17 pitch.. top speed 25 rpm 5400... switched to a 15 pitch 4 blade rpm 5600-5700 top speed 25... know i'm thinking 13 pitch 3 blade Turning Point by hustler. to get rpms up to 6000 lightly loaded. 6-8 people have little effect on performance but when I put 12-17 the engine works way to hard. The problem is prop slip.. I cant find a prop that bites the water and have less than 20% slip. Nutinbitin

That's alot of people to have and expect your boat to perform anything near like when you only have a few in there. I've had 18 on mine and she was way down on speed and pull, but I knew that was going to happen having that kind of weight in there. You figure just 15 people at 150lbs each is 2250 lbs of extra weight. We went out Friday night, 4 of us to dinner with the rear enclosure on, we pulled 5300rpm wot and about 26-27mph. I'm trying to get hold of a 13.75" x 15p and try that out. I still need to get in the water and scrub the bottom of the tunes also.

 

[lakegeorge]

Re: Best Prop Size For Johnson 140 4-Stroke

With all the money that your spending on props you could of bought a 250hp motor. LOL

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

With all the money that your spending on props you could of bought a 250hp motor. LOL

Yeah, but it's people like that, that will save people like me alot of money and time trying all those props out. These 140 motors need to be in the 5600-6200 wot range.

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Well, I got into the water today and scrubbed the bottom of all 3 tunes, with just me and my 10 year old and no gas, with the rear enclosure up, we hit 31 at just about 5500 rpm, still just barely into the wot low range for that motor. It does make a diff. with clean tunes. Need to find me a 14"x15p, think that would do the trick

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

Finally got it, installed a 14" x 15p prop, I have a new boat now. Hits 6200 rpm wot, super hole shot and thrust, hitting mid 30's with a full tank of gas.

 

[glastron50gl]

Re: Best Prop Size For Johnson 140 4-Stroke

Sounds great.... Who makes the prop? I'm still working on finding the right prop. Thanks Nutinbitin

 

[nikogto]

Re: Best Prop Size For Johnson 140 4-Stroke

I got it off this site, super fast shipping, had it within 2 days. Just go to props and put your engine info and find what you need.