Handling issue on pursuit.

[stadiumyamaha]

I've got a pursuit custom build that runs great in a straight line and also in tight turns. The problem is that when I'm in a long sweeping turn the tail wags.
Where should I start tuning?
Strut is neutral, fins are in the water running cc1515 2200kv on 4s2p. Prop is a m545.
Anyone ever experience this or know what's going on?

[siberianhusky]

http://www.modelgasboats.com/Tuning/

One of the best articles I've found on rudder setup and position, as well as some stuff on turnfins.
Sounds like a bit of rudder tuning might be in order to tighten up the stern in high speed turns.
You can probably determine best what it needs from this article some descriptions of different issues.

[stadiumyamaha]

Ill check it out. Thanks

[stadiumyamaha]

Looks light I should try a little pos trim on the rudder per the artical.

[ron1950]

i have very little knowledge of tuning a boat but my pursuit runs a back cut m445 and turns great at all speeds running a 2200kv motor....have u tryed going a little smaller pitch prop?

[lenny]

Hi,
Can you get any videos of it running,
And also of the setup of the boat ?

May be your turn fins are to far down and dragging in the long turns some.

[steinersamuel]

Almost sounds like the transom is lifting?? Prolly some rudder tuning, but currious how many different props you have tried, and if the problem changes. My big apache does the same thing, but ice is upon us now


Green Guys LLC

[Southwest]

Tuck in the rudder a hair and round off the bottom of rudder. My turn fins are higher than the keel line by a good 1/4". No drag.

[tlandauer]

I've got a pursuit custom build that runs great in a straight line and also in tight turns. The problem is that when I'm in a long sweeping turn the tail wags.
Where should I start tuning?
Strut is neutral, fins are in the water running cc1515 2200kv on 4s2p. Prop is a m545.
Anyone ever experience this or know what's going on?

I have the same set up, although motor is a notch below yours ( Leo 4082, 2200kv) , I like the m545 as it has a bit more pitch than the m445 but still doesn't give me heat problem. My turns are ok buy can get unsettled in a long straight if water is not too calm. The stinger that came with the boat was drilled too low, it is flush with the bottom, doesn't give the boat a chance to settle.

[Rumdog]

what position are the turn fins in? I mean, the angle in correspondance with the transom. If they run a little too deep, the outside fin could be catching even though the boat is banked over for a turn.

[Southwest]

Ed Hughey told once the the transom hole should be 5/16"and i interpet it to be to the middle of stringer but that left me alittle in limbo. You know the thickness of stringer comes into play.

[stadiumyamaha]

Ill fiddle with the rudder tomorrow and see if that works. Ill also take a couple of pics of the fins when I get home.
I was also thinking it may be a cog thing but I'm at 28-30% so it should be fine.
It's suppose to be 70 here tomorrow so ill have a chance to run. Sorry to tell you guy up north about that. Lol

[tlandauer]

Ed Hughey told once the the transom hole should be 5/16"and i interpet it to be to the middle of stringer but that left me alittle in limbo. You know the thickness of stringer comes into play.

I think your interpretation is correct, the center hole is 5/16'' above the bottom. I drilled mine on the MHZ Lizard Xtreme 3/8" center above, using Speed Master Stinger and I have no problem with ride issues. I know what you mean by stinger bore thiickness tho.

[stadiumyamaha]

No adjustment on stock rudder. Anyone know of a direct replacement that has some adjustability?

[lenny]

Hey,
If you take the rudder off, You can get some adjustment.
But you need to mod the top hole on the rudder,
You need a small rattail file to oblong the hole or a small reamer.
You could drill a small hole next to the hole to and file out whats left.