i have a ac blast cat with a 27 cc sikk motor and it take over have of the river just to turn around and anyone give me any ideas on how to get it to turn alot sharper please it has no turn fins and has a smaller hitech sterring servo when turning on the remote the rudder looks like its turning enough but in the water it take a huge area to turn it

please give us some more detail regarding your radio gear, battery voltage ? type of servo (torque etc). might be that the servo is not strong enough to push the rudder while running.

You have to use a high torque servo minimum 10kg (352oz) and 3mm (4/40) rod for sterring and if you use a Y harnes and 6 volts works alot better

thanks for the quick response guys heres what im running the battery is MDP 1400 NI-MH
1.2 volts the sterring servo is a HITech HS-645MG the reciever is JR RS310 75 MHZ FM and the radio is a airtronics MX-3S

i have other gas boats and not have them turn in such a big radious it turns almost out of range is how far it take to turn and thats only a right turn it won't even turn left this is a brand new boat had it out 2 time already changed the remote settings and made the rudder turn more but still didn't help in the water

Pic. will be more help

heres some pictures of it

Try to avoid the Z bend from the servo and replace the sterring rod it is not strong enought make one more thiker 3mm (1/8).

What is the voltage of your receiver battery pack? You stated 1.2 volts above but that can't be correct...should be 4.8 or 6.0 volts. I checked the specs of that servo and in my opinion it's not strong enough, especially if used on 4.8v. It produces only 107 oz. of torque at 4.8v. At 6v it produces a little more at 133 oz. It would be acceptable at 6.0v assuming your linkage is done correctly to take advantage of mechanical forces...ie: linkage attached close to servo shaft at servo end and furthest away from rudder at rudder end. This will make the servo use more of it's throw for rudder movement and will give it mechanical advantage. I typically try to use 1/4 scale servos with about 200 oz of torque for steering.

As mentioned, get rid of the Z bend. Also I would suggest a steering arm on the servo instead of the wheel...will allow for linkage setup as mentioned above. Use a heavy duty clevis on the rod, ideally soldered. Keep linkage straight to the rudder, no bends. Use another heavy duty clevis or ball link at rudder. A 4-40 rod has always been sufficiently strong in all my builds. If you want Stainless, a bicycle wheel spoke works!

Hope this helps!

my battery is a hump pack it only says 1.2 on it but has 6 cells i will try what u said and thank you very much for taking your time to help me out all of you guys thanks again

6 cells would make it a 7.2v pack, which is kinda odd. Typically we use 4.8 or 6.0 volts, 4 cell and 5 cell respectively.

I am guessing you have a 5 cell, is that possible. Anyway, work out the linkage to give your servo as much mechanical advantage as possible and make sure the control rod is stiff enough and I think you will be ok!

Keep us posted.