How to settle down a fast 21 SD2

[153stars]

Picked up a Kevlar SD2 ebay fully rigged for 100 less Rec,prop,motor& pipe.Put the newest CMB P&S in mac 21 and CMB nitro pipe. It really cooks she's flying pretty high by the end of straight starts to chime then the instant I turn lays down,turns perfect. Cg is about 10". I had a 440-3 stock on it first when it hit pipe it was insane it would pop the boat out of the water and fly. So I detounged and barr cut it the power band is now very linear and gets right on pipe. I'm keeping the strut even with the keel raised it and lowered it seems about the same. With the 440-3 stock it was alot easier to get on pipe raised. I know there is a throttle but how do i get it to run a little wetter. The rudder is seducer @ 3.75 "per set up" the strut is speed master 2" long a pretty close match for the seducer.

 

[TimothyJones]

HI

I have heard of people taking scotch tape and wrapping it around the rudder about 1/4" from the bottom, like a tail.lenght of tail im not sure maybe a 1" or so.The idea is that the slight drag of tape brings the nose down.

Its a fine adj and won't help a severe problem.

Just a thought, ive seen it on surface drives

TIM

p.s try angling strut 1º at a time, a protractor is good for this.

 

[Chris Wood]

you can put a small amount of angle in 1 degree is to much at once. also try a strut change either up or down

chris

 

[M@MRacing]

I agree with Chris maybe go down a degree on your strut or just call Jerry

 

[Mike Hughes]

Do the tape trick. It is an easy fix. If that is not enough than add the negative angle on the strut. I have also seen Jerry Crowther with a wrench tape under the motor for more wiehgt up front to keep it down.

Mike

 

[153stars]

Do the tape trick. It is an easy fix. If that is not enough than add the negative angle on the strut. I have also seen Jerry Crowther with a wrench tape under the motor for more wiehgt up front to keep it down.

Mike

Is wrench tape lead tape ???? Like golf lead tape.

 

[Mike Hughes]

No. He took a cresent wrench and tape it in the boat of the baot.

Mike

 

[chris1088]

I have used the tape trick and it works vary well .Wow a wrench ? :blink: ! Do what it takes to win!

 

[Russ Nachtweih]

Sounds like it's setup perfectly, use the throttle control!!! I know how hard it is but it does have more than two positions

 

[Joe Warren]

Picked up a Kevlar SD2 ebay fully rigged for 100 less Rec,prop,motor& pipe.Put the newest CMB P&S in mac 21 and CMB nitro pipe. It really cooks she's flying pretty high by the end of straight starts to chime then the instant I turn lays down,turns perfect. Cg is about 10". I had a 440-3 stock on it first when it hit pipe it was insane it would pop the boat out of the water and fly. So I detounged and barr cut it the power band is now very linear and gets right on pipe. I'm keeping the strut even with the keel raised it and lowered it seems about the same. With the 440-3 stock it was alot easier to get on pipe raised. I know there is a throttle but how do i get it to run a little wetter. The rudder is seducer @ 3.75 "per set up" the strut is speed master 2" long a pretty close match for the seducer.

these things will tighen up the boat. Longer Rudder Blade, Push the strut blade down, Dont cut the trailing edge of the prop near the hub & make sure the fuel tank is in the proper length location & Make sure the engine location in hull is correct length from transom per instuctions. If you must run angle in the strut? Something is not located correctly...

 

[TimothyJones]

It easier said than done... thats for sure!!!

Tim

Sounds like it's setup perfectly, use the throttle control!!! I know how hard it is but it does have more than two positions

 

[M@MRacing]

Try the wrench trick first see if it settles downen maybe go negative a degree Jerry uses this trick alot

 

[153stars]

Going through Frank Orlic trials to get one to record speeds he ended up moving motor & tank back 3" around 60 funny things started to happen. Like planting the rear made the hull fly right. It worked well enough he wanted to share it with everyone .Seems a little radical for me to cut up the radio box, I might try adding some weight around to see what happens. I put my hump pack back in instead of the 28 gram pack I had in it. It definitly dosen't to be any faster only better.

 

[Joe Warren]

Going through Frank Orlic trials to get one to record speeds he ended up moving motor & tank back 3" around 60 funny things started to happen. Like planting the rear made the hull fly right. It worked well enough he wanted to share it with everyone .Seems a little radical for me to cut up the radio box, I might try adding some weight around to see what happens. I put my hump pack back in instead of the 28 gram pack I had in it. It definitly dosen't to be any faster only better.

Moving the engine a 1/4 of a inch Backwards is a Big Deal on any Seaducer hull. Seaducer building specs will yield the best all around boat. Unless you are SAW Only attempt?? then Anything goes. Their boats run the best when it is Fast & the strut is set to Spec. if you have to raise the strut to get the speed? You Will give up cornering ability... Most .21 boats corner the best with the Header & the Pipe on the starboard side... & it is much easier on the fingers launching too.

 

[F.Orlic]

My boat was very tight and completly unpredictable going in or coming out of turn. Tried everything including talking to Jerry with no luck. Changes were radical but I had nothing to loose. I'm very happy now, boat is fast and very predictable.

 

[BigChuck]

If you have time and in a need to fix for the next heat. Add 6oz to the top of the main tank. If you can, get it behind the tank. If 6 is not enough make it 9 or 12. I have come to set up my sd more like full size. Cg yes, but also forward ballast. Full size pump the fuel over to burn level and they add or dump water in the forward tanks depending on conditions. WE dump, "fuel burn off", now what are you left with after the 16 and 24 oz are burnt off?? Not every lake you run in will require you to do the weight thing. But it is good to know, the who, what,were and why.

 

[Joe Warren]

My boat was very tight and completly unpredictable going in or coming out of turn. Tried everything including talking to Jerry with no luck. Changes were radical but I had nothing to loose. I'm very happy now, boat is fast and very predictable.

Frank maybe you have a tight hull? many things to consider if the hull is Way tight?. Did you purchase it new? How has it been stored? ( excessive heat is trouble) ) has it ever set for extended time tided down in a boat stand? I have build many of the older seaducer .21 hulls & was always happy with the Performance. I have never built the current longer .21 hull. If you looking for something diff. Mark Hopper builds the Speedmaster .21 Hull. Very Good & FAST .21 mono. I race Only SEADUCER Hulls. But if I built another .21? I would have to consider the Speedmaster .21 Hull. jw

 

[Big roy]

Hello, you can also use lead strips taped or velcro'd under the motor mount ot just in front of the tanks between the engine and tank for ballast. Yes I also have been known to stuff lead weight(s) in the float tubes and zip tie them in place making it easy to adjust weight on the go while out at the pond.

Roy

 

[Jerry_Crowther]

Try the wrench trick first see if it settles downen maybe go negative a degree Jerry uses this trick alot

I do not ever remember using a wrench for weight, But maybe I did at some point. Would be kind of hard to get it in the boat.

If you have the strut straight then you will have positive angle in the strut making the boat want to fly. To set up the strut properly on that boat set the boat on a flat table and have the tip of the strut just touch the table. (Prop End) That will make the strut straight with the hook in the bottom. Then it will run good for you. But with it being such a old boat their is no idea what the owner(s) did before you. Did they sand out the hook or other bottom mods no one will ever know.

So start with the strut like I said and you should be good to go.

Jerry

 

[153stars]

Try the wrench trick first see if it settles downen maybe go negative a degree Jerry uses this trick alot

I do not ever remember using a wrench for weight, But maybe I did at some point. Would be kind of hard to get it in the boat.

If you have the strut straight then you will have positive angle in the strut making the boat want to fly. To set up the strut properly on that boat set the boat on a flat table and have the tip of the strut just touch the table. (Prop End) That will make the strut straight with the hook in the bottom. Then it will run good for you. But with it being such a old boat their is no idea what the owner(s) did before you. Did they sand out the hook or other bottom mods no one will ever know.

So start with the strut like I said and you should be good to go.

Jerry

Thanks for the tip.The black with yellow splatters kevlar hull hasn't been sanded at all ,although a hot car and stand could of affected it at some point.A few club member swapped some cash & boats I ended up with a newer SD3 to run too. It's such a bullet I would like to get the sd2 to run nice though.