Cobra setup?

[Buddy Benedict]

I am needing setup advice for a Cobra tunnel with an OS water cooled motor. I'll be running this in B Sport tunnel.

#1 Prop height: Center of shaft or where?

#2 Balance point: Where should it start out at?

#3 Prop: Currently has a OCT 1440 that looks like a Lynx cut prop

Thanks in advanced.

Buddy

 

[dave roach]

Buddy

Start the engine height about 3/16 from the bottom of the bullet.The balance 7-8 inches from the back of sponson.Prop M440 lynx cut should get you in the water.

Dave

 

[rumrunner]

Just remember no negative trim , also motor can go higher but go slow to find the sweet spot, prop abc 40x53

 

[James montgomery]

What dave said 7-8 inchfrom the back of sponson...so u will want to put your weight if u do put any one it right behind the radio box.....i have about a half of postive degree in my motor...but u might not need to do that with your....i will tell u i have had two of them and they run like they r on rails but they do knd of have a issue of hopping sometimes hard sometimes not as hard but the two i have had have done this so i started useing ax437/3 and a x440/3 with good results it helps with the hop in the boat still goes up and fown a bit but levels outafter a bit.....if u have any other ? I might be able to help u more with your boat i have owned two of them.....i aslo use a x 640 that works good as well....hope this helps....

Here is a pic of my motor on the set up board mine sit high but it works good like that hooe this helps u

 

[Robert Pickard]

The Cobra has a big issue with hopping might take a while to work it out some things on that boat worked for one person but not another just keep testing

 

[John Knight]

Use 8" as the center of gravity measured from the rear sponson tip. Put 1.125 - 1.5 oz in front of the radio box, put 2.5 oz behind the radio box. Put the battery pack in the front of the radio box. Doing this will help with the boat balance and with the hopping. I have watched the Cobras since the came out and they can be set up to run very well. Just will take some working to get it done.

The photo that James has posted shows a lot of engine, lower unit and pipe hanging off the boat. That equates to a lot of weight on the rear of the boat which adds to the challenge to settle it down to reduce and eliminate hopping. The key is to reduce as much weight on the rear of the boat to reduce the weight needed towards the front to get it into a good balance. Think LIGHTER all of the time, especially on a 20 tunnel. Not busting you James. It is just plain physics.

 

[James montgomery]

John good info there i too have weight on the front and on the back of the radio box...i gess i should have said that too...lol.....toke me ahwile to get the hop out of it still does it a little comeing out of the corner but it does level out about ten or fifteen feet out of the corner.....they r a very light boat and run fast when set up the right way...they r not as easy as a vision to set up but that what makes seting a boat up fun and at times frustrating and want to strap some fireworks to it and sink it.... lol hope the info we have gave to u helps out alot....john your not busting me that is good info there info i can even use....lol...

Here is a couple more pics about what john was talking about ....with the weight in the back and in the front and the battery all the way forwar in the radio box...i use double sided tape or velcro to keep it from moveing around in the radio box....good luck with your set up

James

 

[John Knight]

James,

Recommend you put the weight behind the radio box directly ON the hull deck between the radio box and fuel tank. If you can put it at the 8" mark. Putting it on the back of the radio box changes slightly the vertical center of weight for the boat and balance. You want all weight directly on the deck and the boat will ride smoother.

BTW, I have a Vision, a very good running boat that is really planted to the water.

 

[Buddy Benedict]

Wow, Thanks for all the info guys. I plan on having it on the water this weekend and I'll let you know how it goes.

Buddy

 

[the german]

Guys

any suggestion about the prop angel and prop heights ?

Thxs

Alex

 

[dave roach]

Read all post and the answer is there.

 

[SayMikey]

Buddy my vs-1 went to paint today. Tunnels are back

 

[James montgomery]

Hey thanks for that nfo jhn will change them around and see if it does any better....lol buddy your welcome.....ask and u shall receive...lol....wish it didnt get so dang cold up here i would love to run all year round and test....lol.....gess here tye cold wether just makes for building more boats....lol

 

[Bruce Clark]

To Mikey and Buddy, you guys going to run stock class or mod with pipe? I'll be waiting for you. LOL

 

[Buddy Benedict]

Bruce, Both of ours will be B Sport. No pipe.

 

[SayMikey]

I told Alan what to do to make those motors run when you boys were struggling. You will struggle to keep up yet again

 

[Bruce Clark]

LMAO