Miss marked prop?

[Faztbullet]

You dont understand setups...with setback jackplates you can run motors higher due to water exiting pad of boat curves upward into prop giving better biter ,less drag,better cooling as less disturbed and better holeshot. Pic 2 post 2 wont work with a jackplate. The doel fin helps as boat is underpowered as prop not large enough to hold up stern..

 

[dwco5051]

Often there is no one prop that serves all purposes. Forty some years ago I had a bass boat that I both fished tournaments with and water skied with family. With one or two people a cupped prop which was a little slower coming out of the hole was 3 or 4 miles per hour faster than the ski prop which was 2" less pitch. Since the boat was always trailered I would just change the prop depending on what I was planning. A 10 minute job on a boat that was always trailered. Problem solved.

 

[Sea Rider]

You dont understand setups...with setback jackplates you can run motors higher due to water exiting pad of boat curves upward into prop giving better biter ,less drag,better cooling as less disturbed and better holeshot. Pic 2 post 2 wont work with a jackplate. The doel fin helps as boat is underpowered as prop not large enough to hold up stern..

Let the OP respond what asked if wanting to do so, So Bug Off...

Happy Boating

 

[Faztbullet]

Its pretty good stuff..I use it to clean the Alabama love bugs off my Tahoe when we vacation.

 

[Sea Rider]

Back to the OP's original post : Why is a there a jack plate at back transom, have your tried powering the boat with the motor siting fully on top transom without the jack plate ? If, so, was the water flow passing under the upper small plate, over the AV plate, or right in middle ?

FB, it's useless to school me regarding jack plates, down here can chop or raise any transom to match those motors whether being S or L shafts for $ 50. Yep, that's the product you need to pour it into yourself....

Happy Boating​

 

[Faztbullet]

Raising and lowering on transom has nothing to do with a jackplate. A jack plate does several things for a motor/hull combo that just transom height settings cannot. Here a few books I highly suggest you get and read..

 

[Sea Rider]

If the OP wants to get the max HP cowl rated out of that under powered 9.8 motor powering a large boat with a maximized prop running towards max 6 K wot range should lower the motor a tad for the water flow to skim right under the upper small plate, that's where Tohatsu's tall gap plates motors likes to be run to achieve top prop thrust. Let the OP decide if wanting to test said motor with removed jack plate, lower a tad the existing jack plate or keep boating as been doing so...

Happy Boating​

 

[Faztbullet]

the water flow to skim right under the upper small plate, that's where Tohatsu's tall gap plates motors likes to be run to achieve top prop thrust.

Splash deflectors and their gap have nothing to do with engine mounting height settings... the set-up you posted is likely the best for RIB's but not for others.

 

[Sea Rider]

Splash deflectors and their gap have nothing to do with engine mounting height settings... the set-up you posted is likely the best for RIB's but not for others.

Really, don't make me laugh that precise setting which have been playing with for the past 15 years works spot on on different light/medium light applications powered with Tohatsu tall gap plates motors to achieve the max prop thrust with a maximized prop running towards max wot rpm range as there's a higher water bed for the prop to grip much better which seems it's extremely difficult for you to mentally dial well.​

The OP's boat is a simple one powered with a trully under powered motor for that size. NOPE your idiotic Merc posted examples you love posting doesn't apply here as those only work well for short gap plates large HP bolt on motors and applications you play with...​

Other issue Nobody is considering whatsoever is your Boating Location, it's not the same running a boat under full power on flat calm water cond say lakes, river, ponds, your bathtub at straight water courses at whatever lower leg plate height you like dialing. It's a cmplete different story boating at open water where the lower leg deals with chop, wind, currents, wavy situations, swells, etc, for those harsh situations the motor will benefit sitting lower for the water flow to skim right under the small plate to avoid Prop Aeration which is key not to count with. BTW, that precise upper plate setting works top for both boating locations, each with their own respective water situations.​

You should always test portable motors while siting flat on transom and check on a wot run on flat calm water cond the combo performance, if need to chop, raise the transom, install a motor mount, jack plate, doel fins it's entirely up to you...

For further clarification and to stop the endless on line lower plates quarrels would be wise for the OP to post his back motor installation to have a look...

Happy Boating

 

[Faztbullet]

When you actually understand the hydrodynamics of propeller shape, design rakes you will find out a propeller is least efficient totally submerged. Here is a lil tid bit for you to try to understand..
A partial submerged propeller (PSP) is a propeller that works in two phases of air and water. Each blade enters into and exits from the water during rotation. It is practically observed that when one third of the diameter of a blade is immersed, it has the best operating performance. It is often recognized as one of the most efficient propulsive devices for high-speed vessels. Its efficiency is primarily attributed to the reduction of appendage drag because most of the propeller assembly is elevated above the water (Young & Kinnas 2004). An additional advantage of using a PSP is that it eliminates cavitation by replacing it with ventilation; the cyclic blade entry from the air into the water opens a ventilated cavity around the propeller which almost completely prevents the occurrence of vapor cavitation

 

[Sea Rider]

Was not going to respond to your last post, what the heck, lets have some fun keeping live the tech quarrel. What posted is pure BS 6 o'ckock tea time on line writting which only works on dry theoretical basis, not on real wet water world practice as many boaters have experienced.

The issue with you is that you give a crap what I've stated about geographical boating location and water conditions, for you all medium size boats with 0 water flow alteration going out under the middle rear hull powered with way under powered tall plates gap motors for such large applications running towards their max wot 6 K rpm range performs exact same on all water conditions ? Is it the same swimming with hand's fingers wide opened or with closed ones ? Which one grips/thrusts more water more efficiently independently of the water cond and pallm size you're swimming on ?

As I'm positively 101% sure about my posting which have experienced at both lower leg's tall plate's gap settings at all possible water cond from flat calm to wild ones will challenge you to a US 500 dollar bet, will know who's right, who's not right after finishing several water tests done under certain tech boating parameters to be future stated. For that will need a guinea pig boater which will probably be hard to find to test ?

Happy Boating

​

 

[Faztbullet]

What you posted is pure BS... The designs of propellers are done in labs and hydraulic testing and formulas ..Something that way above your intelligence level as anyone can see from some of your posts. The gaps between splash deflectors have no effect on motor. RIB will need to run deeper than fiberglass rigid hull. Which hand is faster a flat hand or a cupped?

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.653.1108&rep=rep1&type=pdf

 

[Sea Rider]

Wow, you blow my mind way further each time you reply to my posts. Guess what ? this post is all about an underpowered 9.8 OB with a 3 blade standard prop powering a large alum open boat, has nothing to do with running large racing hulls powered with large HP motors propped with clever type props running at close water scenarios on flat no wind water cond at straight water courses while clowning as in your avatar pic.

Until now you don't understand, you don't give crap understanding or it's something related to aging badly that Racing Boating has nothing to do with Family Recreational Boating scenarios, who are you trying to fool, locate yourself !!

As FaceBook has not accepted the challenge bet preffering to fly over the cuckoo's nest with his last post giving more firmness to what he usually likes posting about, it's still open to anyone that thinks that my well documented underpowered motor posts are pure BS, will be the only defenitive way to know who's right, who's not....

Happy Boating ​

 

[JimS123]

I just figured out what the true story here is. Its not ocean or fresh or salt or lakes and rivers, or tohitsu plates, its all about the equator.

Boats, motors and spark plugs were all invented by Americans. We are above the equator. The japans merely copied us, they never invented the stuff themselves. Regardless, they are north of the equator as well.

So, the issue is that south of the equator motor height and propeller design are all askew, since the water circles the drain oppositely.

 

[Faztbullet]

Need to go back to using your old screen name as it describes you and your thought processes to a tee......LOCO

loco​

[ loh-koh ]
noun, plural lo·cos.
locoweed.
Slang. an insane person; maniac.
Slang. to cause to be insane or crazy.
adjective
Slang. out of one's mind; insane; crazy.