Prop Ventilating .

[nccatfisher]

I am betting that sooner than later you are going to regret moving that weight to the back.

 

[Stumpalump]

A budget way to run power to the bow is repurposed booster cables. I watch for the good long ones to come on sale. I’ve done this on a couple boats both stern to bow and vice versa. Don’t really need a cranking battery with these smaller engines, I just use the deep cycle. Saves an extra battery weighing the boat down.


Sent from my iPhone using Tapatalk

Thats a good idea. If he runs the batts down for some reason he can always pull start it. I pull started the 60 one day with a piece of paracord wraped around the flywheel. It’s really easy but his 30 may have a pull start built in. When I wanted to buid an extension cord for the welder the price of wire was expensive. An RV extension cord of the same guage was dirt cheap so I cut off the ends and used it. A refrigerator extension cord is stought as well. They list the wire guage on all extension cords.

 

[Weldorthemagnificent]

I’m betting between the batteries downsized and relocated and the hydrofoil, it will have a better attitude in the water. If the rpms are still low, get a replacement prop according to a prop calculator. Stock aluminum is all that’s needed for this application so price won’t be crazy. Speed won’t be huge with a boat this size and weight with that motor but it should be able to carry a couple fishermen and gear and still plane. They are super reliable motors, mine is a 1983 35hp and still runs flawlessly.


Sent from my iPhone using Tapatalk

 

[DarrellS]

nccatfisher : I hope your wrong , I'm pretty unsure of what to expect , but with the weight up front the bow would just spear into the waves .
If I had a way to lower the engine then I might have been able to find a sweet spot , but until a jack plate comes along I am forced into trying this to make the boat usable .
The Rockwall Texas area has wind on the lakes on most days , and the wind speed feels like it is twice as strong as the forecast says .
I don't expect to be able to enjoy two foot waves but I want to be able to fish in 10-15 mph winds when the waves are in the one foot area .

 

[nccatfisher]

nccatfisher : I hope your wrong , I'm pretty unsure of what to expect , but with the weight up front the bow would just spear into the waves .
If I had a way to lower the engine then I might have been able to find a sweet spot , but until a jack plate comes along I am forced into trying this to make the boat usable .
The Rockwall Texas area has wind on the lakes on most days , and the wind speed feels like it is twice as strong as the forecast says .
I don't expect to be able to enjoy two foot waves but I want to be able to fish in 10-15 mph winds when the waves are in the one foot area .

Well I MAY be wrong. But as a heads up I have a similar size boat and I MOVED two group 27 batteries to the front and made a built in fuel tank (11) gallons that goes all the way across the front right behind the casting deck just to get all the weight I could forward. That is with a 25 HP motor and it made it perform tremendously better. My motor sets a little higher than yours on the transom but it is set back 5" it also has power trim.

 

[DarrellS]

nccatfisher : with your experiences do you think your success with all the weight up front is because of the jack plate ?

 

[crappie777]

nccatfisher-Is that 25 hp with power trim a 4stroke? Set back 5 inches? If so I can see why you need weight up front.

 

[Weldorthemagnificent]

Try it the way it is before making any changes. Then get the rpms right before adding a jackplate.


Sent from my iPhone using Tapatalk

 

[nccatfisher]

nccatfisher : with your experiences do you think your success with all the weight up front is because of the jack plate ?

Doesn't have a jack plate, just T&T.

 

[nccatfisher]

nccatfisher-Is that 25 hp with power trim a 4stroke? Set back 5 inches? If so I can see why you need weight up front.

Yes it is.

 

[DarrellS]

Got out in the boat today . 36 degrees . Son and his new wife wanted to go fishing with me . With the 3rd person sitting in the seat on the back casting deck the boat would go 18 mph , on plane with 8 inch swells and 15 mph winds . No problems holding the bow up and over waves .
I went for a quick solo ride and it was a completely different boat , very quickly hopped up onto a plane and ran strong to 26 mph .
The tachometer barely made it to 4600 rpm .
This is the nicest the boat has ever ridden on the waves .
I'm very happy with the Davis hydrofoil , I never would have thought a hydrofoil would influence ventilation .
Now to get the Tachometer checked and get a good prop on there .

 

[Stumpalump]

Thats great news! What specific Davis fin did you use? I love what they do especially in rough water if you play in the wakes. You need to determine prop pitch next. There should be numbers stamped between the blades or sometimes you need to unbolt it and read the numbers on the hub. If all is good with the tach then you should have a 15” prop according to your numbers. If your tach is off you probably have a 13”. You probably need a 13”. Not sure whats available for a 1990’s vintage 30 hp but a 12 would work. If a prop change is needed then your gonna love what that does as much or more than your other mods. Whats the pitch?

 

[DarrellS]

Thats great news! What specific Davis fin did you use? I love what they do especially in rough water if you play in the wakes. You need to determine prop pitch next. There should be numbers stamped between the blades or sometimes you need to unbolt it and read the numbers on the hub. If all is good with the tach then you should have a 15” prop according to your numbers. If your tach is off you probably have a 13”. You probably need a 13”. Not sure whats available for a 1990’s vintage 30 hp but a 12 would work. If a prop change is needed then your gonna love what that does as much or more than your other mods. Whats the pitch?

The prop is a bit of a mystery to me , It does not have any numbers on it that are visible . Have you ever seen a prop that might have numbers that can be found on a surface thats only visible once its removed ?
So I now have 3 group 24's at the transom and the 18 gallon fuel tank is in front of the the batteries .
Here is the Amazon link to the Davis instruments XL fin that I have on my boat thanks to my son and his other Heathen friends LOL .
They installed it under the cavitation plate and shifted it forward until they could use the bolt for the trim tab which was already missing .
https://www.amazon.com/gp/product/B001QUS4JM/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

 

[Weldorthemagnificent]

For comparison, my utility v hull at 300lbs, one batt, one trolling motor with a 35 johnnyrude has a 13” pitch. It will carry 3 guys and go low 20’s. Alone it flies! I would imagine if you did a prop calculator, it would say to use an 11” pitch prop. That would allow the motor to run at the proper rpm and probably pick up both power and a pinch of top end.


Sent from my iPhone using Tapatalk

 

[GYPSY400]

Is there a reason you need 3 batteries? Is your TM 24V ?

Your rpm is slightly low at 4500.. Once you iron out that your tach is working properly you should aim for 5000-5500 riding solo with average weight load. I'm betting that you have a 13P now and need an 11P

For reference I run a 30hp mercury tiller 2 stroke on a 16ft. Prop is 10"diameter by 11"P.. max rpm solo (with fishing gear) is 5600 and speed is 45km/h.

Sent from my SM-G903W using Tapatalk

 

[Stumpalump]

Look between the blades on the hub. The faint stamping is often hidden by paint. If not yes you have to pull it off and look at the hub. I used a prop calculator asuming 2.23 gear ratio your mph, and RPM. I put in the standard 10% slip to come up with 13p. Thats a guess working the calculator backwards so the guys with real world experiance is better. Small props slip more than 10% as well. Here are some props I had laying around showing the different locations for the stamp.


If anybody needs this yamaha 25 prop let me know. I think its new.

Sorry the pics wigged out on me but this tiny yamaha prop is new and wasting away in my shop as well.
2.5hp ? These show all the different places you find numbersand some are very faint and have been painted but you can always find the numbers.

 

[DarrellS]

Stump : Thanks , I will pull the prop to see if I can read the hidden numbers .
Gypsy : Yes the trolling motor is 24 volt , 60 inch shaft Terrova , only a few months old , I would not have bought it if I knew it was going to stay on this boat .
I bought the trolling motor used for half price from a guy that used it twice and decided he wanted power stow and deploy .
80 lb thrust is absolutely overkill for a 750 lb boat hull .
at anything over power level 6 it will jerk the boat out from under you if you are not on your toes .
I know that I will be selling this boat and I will end up with a deep V like a Lowe lunker or a similar design which is why I wanted the long shaft .
In about the 1 ft waves we were fishing in on Monday the trolling motor never came out of the water with about 40 inches of shaft let out .

 

[GYPSY400]

^^ better with more trolling motor than not enough. At least the batteries will last a long time

Sent from my SM-G903W using Tapatalk

 

[DarrellS]

Okay , So for a update on this problem solving . I was finally able to get down to the shop to pull the prop and try to identify it . It looks like its manufactured brand is Vortex , And is stamped with a 13 .
It turns out that with just me in the boat and a empty live well it still wants to ventilate at about 25 mph and the RPM is right at 4200 rpm .
So I will be trying to get a different prop to fix the RPM Problem , and then go for a test ride to check if the ventilation continues .
I have scrounged up a 5-1/2 set back CMC power jack plate with a dead actuator .
I am thinking about putting the jack plate on and just locking the bolts to hold it in position .
I can't even begin to justify the cost of a 400.00 actuator .

 

[DarrellS]

So I just ordered the Hustler Prop Part Number 21201110 .
Prop Model Number R1-1011 .
Diameter X Pitch 10.5 X 11
Installation Kit Brand MasterGuard
Kit Part Number 11200200
Kit Model Number 22
These are the parts per the prop wizard recommendations .
Since I currently have the 13 I'm hoping the 11 is a move in the right direction .
With any luck the parts will arrive around Feb 20 .
Hopefully the weather will be good enough to give it another try .