This is just an idea. How is the throw for your rudder? Maybe the throw is too short, causing you not to turn very sharp. Also all of the other advice is great and should be checked. also if a V hull you should have a turn fin on the boat.

Regards
Tar:cheer:

On the radio whats the end point set at?I usually set mine around 40 to 50% of the max throw.Also its possible your dual point on the radio got turned.I would check your radio then while is on grab the rudder and turn the steering it should move the boat if not your servo is weak.There should be no play in the linkage if so i like ball end links.

It could be 1.2 volts per cell or 1.2 amps/1,200 mah.
It looks liek you have a Hi-tec 645-MG servo in there which should have plenty of torque.
Are you having problems steering both ways or just when making left turns? Cat's don't seem to like to make high-speed left turns.
The only other things that I can think of are what was mentioned above, not enough steering throw on the transmitter.

Tar18 wrote:The boat is Ac Blast cat as he said in the first post no need turning fins

Bruce Carrigan wrote:
It depends how long is the servo horn mine is set at 65% (we'r talking about the EPA),as for the ball end links they are good but I prefer the ez connecters www3.towerhobbies.com/cgi-bin/...LXK103&P=SM they are much easyer to adjust

the hump pack has 5 cells not 6 sorry

im going to put a new linkage on it and a 1/4 scale hitech servo and try that it should help i will let you know how it works thanks for all the help

yes it has 5 cells sorry and on tuesday im going to goto the hobby shop to get a stiff rod and i need a servo arm i dont have one to fit my 1/4 servo and when i get it together im going to take it to the river and i will let u guys know how she works thanks again all u guys for your help

sorry it took a week to reply but i just had it out today since the last time i made a post because of the weather i put a 1/4 scale hitech servo on it instead of the small one that was on it i didn't put a stright rod on it because i would have to make new holes in the hall so i just tried it with just the big servo and now it turns on a dime 100% improvment the difference between night and day so i will keep the z bend into it because its working just fine with the bigger servo so i just wanted to let you know that the help you guys gave worked and im graitful for the help thank you guys very much for helping me out:P

Yep, 1/4 scale all the way! That's all I run in my boats. If you use a regular size it better be a GOOD quality digital with metal gears...otherwise much safer to go with a 1/4 scale. I use Hitec 755MG on 6.0v... good servo for the price.