Jet boat Cobra fins or Thrust vectors

jbg · 05-30-2012, 09:16 AM

Hi all. I really appreciate all of the insight extended by the experienced people on this forum. I am not new to boating but somewhat new to the Lakes Region. I've owned boats in the past but never a jet powered one. I currently have a Yamaha jet boat and the low speed handling is horrible and sometimes scary to say the least. Does anyone have any experience with steering fins? More specifically, the Cobra or Thrust Vectors. Thanks in advance.

NoBozo · 05-30-2012, 09:46 AM

Plug this into Google without the quotes: . Plenty of info, including videos.

NB

"Cobra or Thrust Vectors"

NH_boater · 05-30-2012, 01:05 PM

I owned a Yamaha jet for over 5 years and loved it. I only sold because I bought a house in Alton bay and the trip into the broads got to be to rough on too many days so I got a heavier, deeper V boat. The small draft makes for a fairly flat bottom design and you get a pounding in larger seas.

I spent the first season without cobra fins and it was tough to move around the docks and on and off the trailer if there was a good wind. Put the fins on and instant difference. You will find that you get great handling in forward and pretty good handling in reverse. I got to the point that I could put it anywhere as well as any stern drive I saw. I could spin it around in its own length, impressing many on lookers. Get them and you will not regret it. There are a few different styles so look closely. The newer ones are best with their larger profile. Besides low speed handling, they also improve tracking (avoiding side slip) at speed as well. They are very easy to install yourself. By the way, you can still do spins with them on, you just won't get quite the same slippery spin action. I am sure my experience from first season to second season accentuated the fins but they really work. I could never understand why Yami did not get around the patent with their own design.

I would recommend the 'pin' plug fix for sure. A blown plug when you least expect it is very frightening. If you have a 2-stroke, I would recommend replacing the oil lines with good aftermarket ones with stainless clamps. Otherwise you could easily loose a motor.

Have fun!

tom-sr230 · 05-31-2012, 08:22 AM

as a yamaha 23 foot jet boat owner going on 8 years i have never used any of the add-on fins ...just practice..take her out when the water is calm to "get the feel" of the boat by yourself to gain the confidence you will need when you are out on the water near other boats and docks ...try to use the "bump the throttle method" when you need to steer as you need to have thrust to steer.
I highly recommend that you join a forum called "yamahajetboaters.com"
the site and the people on it are a wealth of information, everyone helps one another with questions and this issue you brought up on this forum is one of the major topcis discussed there.

in your post you did not mention what model or year your boat is?

TOM

tom-sr230 · 05-31-2012, 08:27 AM

also as nh boater pointed out make sure that your clean out plugs are locked in by giving them three good pulls after they are set in the tubes but i would suggest purchasing a plug pin fix to prevent them from blowing out..trust me it is not fun to have a plug plowout. it could damage your clean out tray and the access hatch.

TOM

jbg · 05-31-2012, 12:41 PM

Quote:

Originally Posted by tom-sr230

also as nh boater pointed out make sure that your clean out plugs are locked in by giving them three good pulls after they are set in the tubes but i would suggest purchasing a plug pin fix to prevent them from blowing out..trust me it is not fun to have a plug plowout. it could damage your clean out tray and the access hatch.

TOM

Thank you everyone. It's a 2012 SX210. I check the clean out plugs before each outing. I have read some things on other forums and probably would not have been so conscious of this had it not been for the good advice of those who have had the misfortune of going through this. I'm actually installing the locks this weekend.

tom-sr230 · 05-31-2012, 01:23 PM

which locks did you buy?
also i would suggest a keelguard for when you want to explore those shallow waters or beach the boat.
two years ago i tried a folding box anchor made by slide co. as it was suggested on another forum and it was the best i have used .. i now have two..one for the bow and one for the stern.
just like you said ..you can learn a thing or two from someone who has been there before!!
when you are out on the water look for us..
it is a 2004 black and tan yamaha sr-230 with a white hull..
we usually hang out at the sandbar near the margate hotel
and around ragged island..
good luck with your new boat and enjoy all the mods you can and probably will do..

05-30-2012, 09:16 AM	#1
jbg Junior Member Join Date: May 2012 Posts: 13 Thanks: 0 Thanked 1 Time in 1 Post	Jet boat Cobra fins or Thrust vectors Hi all. I really appreciate all of the insight extended by the experienced people on this forum. I am not new to boating but somewhat new to the Lakes Region. I've owned boats in the past but never a jet powered one. I currently have a Yamaha jet boat and the low speed handling is horrible and sometimes scary to say the least. Does anyone have any experience with steering fins? More specifically, the Cobra or Thrust Vectors. Thanks in advance.

05-30-2012, 09:46 AM	#2
NoBozo Senior Member Join Date: Jun 2008 Location: Portsmouth. RI Posts: 2,231 Thanks: 400 Thanked 460 Times in 308 Posts	Plug this into Google without the quotes: . Plenty of info, including videos. NB "Cobra or Thrust Vectors"

05-30-2012, 01:05 PM	#3
NH_boater Senior Member Join Date: Jun 2007 Posts: 298 Thanks: 14 Thanked 147 Times in 62 Posts	I owned a Yamaha jet for over 5 years and loved it. I only sold because I bought a house in Alton bay and the trip into the broads got to be to rough on too many days so I got a heavier, deeper V boat. The small draft makes for a fairly flat bottom design and you get a pounding in larger seas. I spent the first season without cobra fins and it was tough to move around the docks and on and off the trailer if there was a good wind. Put the fins on and instant difference. You will find that you get great handling in forward and pretty good handling in reverse. I got to the point that I could put it anywhere as well as any stern drive I saw. I could spin it around in its own length, impressing many on lookers. Get them and you will not regret it. There are a few different styles so look closely. The newer ones are best with their larger profile. Besides low speed handling, they also improve tracking (avoiding side slip) at speed as well. They are very easy to install yourself. By the way, you can still do spins with them on, you just won't get quite the same slippery spin action. I am sure my experience from first season to second season accentuated the fins but they really work. I could never understand why Yami did not get around the patent with their own design. I would recommend the 'pin' plug fix for sure. A blown plug when you least expect it is very frightening. If you have a 2-stroke, I would recommend replacing the oil lines with good aftermarket ones with stainless clamps. Otherwise you could easily loose a motor. Have fun!

05-31-2012, 08:22 AM	#4
tom-sr230 Member Join Date: May 2012 Location: north of boston/and paugus bay Posts: 35 Thanks: 3 Thanked 2 Times in 1 Post	as a yamaha 23 foot jet boat owner going on 8 years i have never used any of the add-on fins ...just practice..take her out when the water is calm to "get the feel" of the boat by yourself to gain the confidence you will need when you are out on the water near other boats and docks ...try to use the "bump the throttle method" when you need to steer as you need to have thrust to steer. I highly recommend that you join a forum called "yamahajetboaters.com" the site and the people on it are a wealth of information, everyone helps one another with questions and this issue you brought up on this forum is one of the major topcis discussed there. in your post you did not mention what model or year your boat is? TOM

05-31-2012, 08:27 AM	#5
tom-sr230 Member Join Date: May 2012 Location: north of boston/and paugus bay Posts: 35 Thanks: 3 Thanked 2 Times in 1 Post	also as nh boater pointed out make sure that your clean out plugs are locked in by giving them three good pulls after they are set in the tubes but i would suggest purchasing a plug pin fix to prevent them from blowing out..trust me it is not fun to have a plug plowout. it could damage your clean out tray and the access hatch. TOM

05-31-2012, 01:23 PM	#7
tom-sr230 Member Join Date: May 2012 Location: north of boston/and paugus bay Posts: 35 Thanks: 3 Thanked 2 Times in 1 Post	which locks did you buy? also i would suggest a keelguard for when you want to explore those shallow waters or beach the boat. two years ago i tried a folding box anchor made by slide co. as it was suggested on another forum and it was the best i have used .. i now have two..one for the bow and one for the stern. just like you said ..you can learn a thing or two from someone who has been there before!! when you are out on the water look for us.. it is a 2004 black and tan yamaha sr-230 with a white hull.. we usually hang out at the sandbar near the margate hotel and around ragged island.. good luck with your new boat and enjoy all the mods you can and probably will do..