phil thomas sport 20 blowing off.

[tmunn]

Guys if it is the slightest bit choppy or a bit of wind or i cross another wake my boat gets very light on the sponsons.

also when i make a wide turn it will do something like a hop around the turn (for lack of a better word).

I don't thing it is the turn fin as that is mounted EXACLTY per phil's and dick's instructions .

The boat is nor hooking or pulling or spiining out only hopping around the turns and will get really light and sometimes even blow off.

would you guys suggest dropping the strut first and tring that or adding weight to the nose.

I know the boat is tail heavy and according to my calculations would need about 6 oz of weight to the forward sections of the sponsons to balance at 14" forward of the transom with no fuel.

I know how many of you feel about adding weight but ya gotta do what ya gotta do <_<

Any suggestions

Thanks

Terry

 

[P THOMAS]

You should have the balance close if you installed radio box and the motor as far to the front as possible. I dont recall what setup you have now. if your balance is not close you will have the strut too deep to compensate. When the boat gets loose on the water the rear balance problem will make it blow off instead of flying level till it is back on the water. same goes for a nose heavy boat it will stuff the nose in.

Once you have the boat speed up and are happy how the boat rides you can add some stik on weight strips right next to the motor, which is near the balance point, to have it stay on the water in gusty winds

here is the setup info I thought you got a copy of the setup?

PHIL

9. TRIMMING THE BOAT

The 1 1/16” inch strut depth is a good starting point. If the boat rides too light on the water, adjust the strut deeper. If the front sponson are running too hard on the water adjust the strut higher until the boat rides flat on the water but will not blow off. Small adjustments to the strut angle can be made also. Weight can be added to the nose to fine trim the hulls balance point if needed. The hull should balance about 14 inches from the transom without fuel.

 

[tmunn]

You should have the balance close if you installed radio box and the motor as far to the front as possible. I dont recall what setup you have now. if your balance is not close you will have the strut too deep to compensate. When the boat gets loose on the water the rear balance problem will make it blow off instead of flying level till it is back on the water. same goes for a nose heavy boat it will stuff the nose in.Once you have the boat speed up and are happy how the boat rides you can add some stik on weight strips right next to the motor, which is near the balance point, to have it stay on the water in gusty winds

here is the setup info I thought you got a copy of the setup?

PHIL

9. TRIMMING THE BOAT

The 1 1/16” inch strut depth is a good starting point. If the boat rides too light on the water, adjust the strut deeper. If the front sponson are running too hard on the water adjust the strut higher until the boat rides flat on the water but will not blow off. Small adjustments to the strut angle can be made also. Weight can be added to the nose to fine trim the hulls balance point if needed. The hull should balance about 14 inches from the transom without fuel.

Each time i try balancing the boat on my fingers as you suggested the model seems very tail heavy.I have the rear radio box mounted about 7/8" from the step in the hull as per directions and am running one single 8 oz tank.

The strut is mounted to the outside of the transom.The engine had been premounted so I just went with where the previous owner had started.

check out the thread just below this one i put a link to my gallery there.

here you go phil.....now be easy on me ....

http://www.intlwaters.com/index.php?automo...=si&img=903

thanks

Terry

 

[Mark Anderson]

The first thing to do is add weight to get it to balance where the designer intended. Questions like this drive manufacturers crazy. "I know that I didn't follow the directions, but how do I make it work?" Phil spent alot of time designing and testing the boat, start with his set up and get a base line then go from there.

 

[P THOMAS]

.I have the rear radio box mounted about 7/8" from the step in the hull as per directions and am running one single 8 oz tank.The strut is mounted to the outside of the transom.The engine had been premounted so I just went with where the previous owner had started.

thanks

Terry

OK I see your problem You read the info for the front box setup, it has to be 7/8 back to clear the cowl. The rear box ifyouhave to use that, should be mounted as far front as possible.

Add some lead strips next to the fuel tank in the front till it stays on the water.

I set one upusing the Mac 21 with the front box and a 6 oz tank on the left in the hull and a 1 oz hopper in the right side and the boat has no extra lead added to balance.

I know you have one of the early boats that have the sealed up engine well, so you would have to cut the access holes out to install tanks in the hull.

 

[P THOMAS]

The first thing to do is add weight to get it to balance where the designer intended. Questions like this drive manufacturers crazy. "I know that I didn't follow the directions, but how do I make it work?" Phil spent alot of time designing and testing the boat, start with his set up and get a base line then go from there.

HOW TRUE Why do they think all boats have to be MADE TO WORK, Some of us actually do test our setups :lol:

 

[kilr95ss]

Might need to get someone with smaller fingers to set up that front radio box for 'ya! :lol:

 

[tmunn]

The engine and rear radio box holes were already drilled when I purchased the boat so i tried to use what was there.

I am pretty new to this and stand to be corrected but i would be hard pressed to beleive that moving the rear radio box up closer to the step in the engine well would be enough to compensate for the tail heavieness.I will loosen the box some day and try it.

Here is what i did for now and it works excellent..

I added 3oz of tape weights to inside of the sponsons at the top/inside as an experiment..NOT pretty but wow what a difference.

I figured that i could get away with less weight farther forward than inside the engine well up by the tank <_<

I am going to leave them there and if they fall of i will replace them only epoxy them in place.

Or

put the weight in beside the tank but I think i would need a fair bit more than 6 oz back there

It was far more windy and choppy than any other outing and she never blew over once and the was nice and flat the whole way around the track.

It looked like it was riding more on the prop and not the rear of the boat giving it the nose up attitude.

It seemed to skip across the chop more evenly as opposed to plowing through it.

when it hit the chop the whole boat seemed to pop up more evenly instead of trying to blow over.

I also experimented with the strut depth and with the added weight it did not seem to make a lot of difference.but it was pretty rough at times.

I am anxious to see how she handles crossing another boats wake but i do not think it will be a problem.

Tonight it worked excellent and went straight and around the markers like it was on rails.

No sign of trying to blow off or stuff into the water.

I AM NOW VERY PLEASED WITH THE HANDLING AND THE BOAT.

Just one more issue to work out with the engine or prop and i should be good to go.

Kilr 95 you try not to think of me when your fishing stuff outa that front radio box

Thanks a lot Phil and everone else.

I am learning a bit more each day.

Terry

 

[P THOMAS]

Yes dont worry about where everything is on your boat. You have found a better setup and it runs well for you now.

Everyone will do some things different and each boat has to be trimmed. Rarely two will be the same.

 

[Joe_Knesek]

The first thing to do is add weight to get it to balance where the designer intended. Questions like this drive manufacturers crazy. "I know that I didn't follow the directions, but how do I make it work?" Phil spent alot of time designing and testing the boat, start with his set up and get a base line then go from there.

HOW TRUE Why do they think all boats have to be MADE TO WORK, Some of us actually do test our setups :lol:

Because not everyone believes running a 2 foot long steering pushrod & running the fuel ahead of the CG is a good thing.

 

[tmunn]

I could not get my fuel in the sponsons like i would have liked without major cutting and rework... but it seems to be working well and will be more testing on the weekend.

For me the rear radio box and front tank seems to be fine.I know the theory behind tanks over the c/g but could do it easily this time..Next boat though...

i hated to add weight but i pretty much had to.

Joe

Do you have any pick of your finished boat I would like to see your radio box and tank(s) setup please.

Terry

 

[Joe_Knesek]

I could not get my fuel in the sponsons like i would have liked without major cutting and rework... but it seems to be working well and will be more testing on the weekend.For me the rear radio box and front tank seems to be fine.I know the theory behind tanks over the c/g but could do it easily this time..Next boat though...

i hated to add weight but i pretty much had to.

Joe

Do you have any pick of your finished boat I would like to see your radio box and tank(s) setup please.

Terry

Terry since the tanks are in the side you can't see them. A photo of the radio box is in my gallery.

 

[P THOMAS]

Terry, here are some pictures of my new boat, the front radio and the side tanks do work well. I dont have any extra weight. This boat also has the transom mounted strut.

https://www.intlwaters.com/gallery/displayimage...=305&pos=20

PHIL T

 

[tmunn]

perhaps it where i have things installed ot something.With the original setup and front tank and reaer radio box it was tail heavy and would blow off no matter how deep the strut was.

with the added weight it works much better.

i may look at using the same amount of weight or less right inside the tank and see how it acts but for tomorrow i am leaving the weight where they are and see how that goes..

at some point i may move the radio box ahead some to help with balancing but it is mounted well now and not leaking so i hate to mess it up.

is there any need of a hopper tank if the 8 oz is being sucked dry.

room is tight with my tank slanted to clear the throttle arm.

I could go with a 6 oz and a 4 oz up front if i need a hopper style but it has no problem sucking the 8 oz dry

Thanks

Terry

 

[Mark McCray]

Hi Joe,

The 20 I built for Montana s very similiar to yours. I used Phil's mid boat ox and placed that almost inline with the drop in the hull and one big fuel tank right behind that CMB motor/carb. No extra weight added, and she runs like its on rails. It sounds as if Montana will have some competition this summer.

Mark

 

[Joe_Knesek]

Hi Joe,
The 20 I built for Montana s very similiar to yours. I used Phil's mid boat ox and placed that almost inline with the drop in the hull and one big fuel tank right behind that CMB motor/carb. No extra weight added, and she runs like its on rails. It sounds as if Montana will have some competition this summer.

Mark

Thanks Mark. Emily is going to run in the regular classes this year.

 

[Mark McCray]

Hi Joe,

Montana will be looking for some competition in the 20 hydro class. Brandon, The Duke, were the steady racers in that class. Emily will halp to fill up the class even more.

Mark