Another steering issue

[bluejay2]

1989 Mainer 175- 18 Starcraft Fiberglas boat pulls HARD right. Tab under a-cavitation plate direction has NO affect. Is the problem the 4 blade prop, motor set too high? Will skeg torque tab steering stabilizer correct problem? Seems like a simple solution if it will work, would rather not have to install no feedback steering which will only mask the problem.

 

[Bondo]

Re: Another steering issue

Is the problem the 4 blade prop, motor set too high? Will skeg torque tab steering stabilizer correct problem?

Ayuh,... Possibly, Possibly, 'n Probably....

Try a different prop...
Try a different motor setting...
Or,...
Try a torque tab...

 

[Fed]

Re: Another steering issue

Tab under a-cavitation plate direction has NO affect.

Just to be clear the trailing edge of the tab should be turned to the starboard side to correct this.
Trimming your motor 'out' will also help, trimming 'in' too much changes the attack angle of the prop blades and will cause your steering to pull.

 

[bluejay2]

Re: Another steering issue

The diection of the tab has 0 effect, almost like it's not getting water to correct the pull. Trimming the motor also has no effect on the situation. Any other ideas?

 

[Fed]

Re: Another steering issue

Aside from being a steering tab they are also an anode, does it look 'full size' or could it be eaten down some?
I had a problem with a pair of 80s on a cat and my friendly Merc dealer put me onto some oversized tabs that Merc made, might be worth a try asking your local dealer.
Does it happen at cruise speed of say 30mph or only under hard acceleration?

 

[bluejay2]

Re: Another steering issue

Tab is like new, in fact I tried a brand new one and had the same results. Hard pull happens from plane-off to wot. Oversized tab sounds good, so does the skeg tab sold by a number of sites including Bass Pro. Does anyone have experience with the skeg tab?

 

[Fed]

Re: Another steering issue

What's your prop pitch, WOT rpm, speed & cav plate height relative to the very bottom of the hull?

 

[bluejay2]

Re: Another steering issue

Prop is 4 blade with 21 pitch. Cavitation plate is 2 inches above bottom of deep V boat. RPM and speed not now available since boat has been winterized.

 

[Fed]

Re: Another steering issue

The quick google I did on your "18 Starcraft" didn't come up as a particularly deep V and I got both fibreglass & alloy boats, have you got any rear end pics of your boat to show us?
It must really fly with a 175hp on it, do you think that maybe half the fin is out of the water at any sort of speed?
I'm thinking it may steer better if the motor was a bit lower.
What do you use the boat for? It's not what you'd call a 'normal' combination, more like an Exocet missile.

 

[bluejay2]

Re: Another steering issue

Boat is 1989 Starcraft Tournament 180- a heavy(2500# wet), wide walleye boat rated for 175 hp. Top speed is around 50 and hole shot is adequate. Boat is not overpowered and is very stable at all speeds. There is only one hole left to lower motor before top bracket rests on transom. Am I going to get improved steering by dropping the motor one inch?

 

[Fed]

Re: Another steering issue

Dropping it down would be my first choice.

 

[Bondo]

Re: Another steering issue

Hard pull happens from plane-off to wot.

Ayuh,... Has it always done this,..?? If not, what changed when it began,..??

Is the hull, 'n it's strakes Straight, 'n True,..??
Is the skeg bent on the motor,..??
Have ya got a Different prop to try,..??
Is the motor mounted square 'n true, 'n centered on the hull,..??
( a hint for answerin' the last question,.. Look at the hull's Bottom,(the keel line) not the top)

 

[bluejay2]

Re: Another steering issue

Motor is centered, hull is true, skeg is straight. This leaves the options of dropping the motor 1 inch, trying a different prop, no feedback steering, or a skeg torque tab for $20. The torque tab seems the easiest and least expensive option and the most viable solution. Again, has anyone had experience with using one?