Set up and Rudder Length for Mean Machine/Sprint Cat 29"

[78MaicoRider]

Got the Sprint Cat in the water today with a Turnigy Marine 180A ESC replacing the 180 Seaking that I blew up. The boat ran pretty good. A little sluggish until on plane. But once planing, it moved with good speed. About 2X faster than with the Seaking ESC. (It used to be a slug) I think my lack of speed before was due to not getting full throttle. I was using Tactic RX and TX. I have changed to a RadioLink RC3S. which I can cal the ESC at 100% on the TX. Then set the TX to 120%. Read somewhere this is the way to be sure you are getting Max throttle. Although it may be causing an issue. I brought it in for a 1 min run temp check and red led was flashing on ESC. With M445 prop, ESC was 103, motor 105, batts 95, ambient temp 95. Everything running cool. But I cant see water coming from the outlet when running. So I don't think I am getting enough flow for hard running or M545.

My questions are,
1. Any comments on the above?
2. Anyone increasing the size of the water pickup hole in the rudder?
3. I know my rudder is too long. What length rudder works best for Mean Machine/Sprint Cat 29"? I think someone said 3 1/4" below the ride pads. Mine is 4 3/8".

[Chilli]

Disconnect the cooling tubing at the outlet and blow a mouth full of water and see what you get coming out of the rudder. You should get a solid stream coming out of the pickup hole. If not, look for the block.

I had a MM with the same rudder a while back. I trimmed it 1/4 inch but was afraid to do any more.. There were allot of folks who built them back then and we were warned not to cut the rudder down too much or the boat would spin out in the turns.

[78MaicoRider]

Took the Sprint Cat to the pond again. The low water flow that I saw before is due to the outlet being the larger than the fittings on the motor and ESC. Got good speed from it on first set of packs. The 2nd set was slow. An older set of Nanotechs that are most likely done. This is something I don't have very good luck with is batteries. After the first run one of the packs from the first set was 125 the other was 105. They are two 3s 5200mah 45C packs in series. So I expect the hot one to die soon as it took a lot longer to balance as well.

[ray schrauwen]

Running 6s1p can be very hard on batts and esc.

[chipgibbs]

You have'nt said anything about the Timing setting. The only time I had an issue with a Seaking 180 overheating was when the motor timing was not set correctly.

ChipG