So I have had my (new to me) first go fast boat, an 1987 Baja 240 sport with a Tyler Crocket 610hp 502 out a few times now on Lake St Clair and I have some questions.

When getting around 65 MPH, the steering shakes violently and gets hard to control. This is Chine-Walk correct? What is the best way to correct this? The boat has Bennett trim tabs.... I was thinking about buying a Steering stabilizer that I seen Drew Marine sells (was thinking about buying a single).

Any pointers you guys can give me?

Thanks

full hydraulic steering

X2! I would check to see right now if your outdrive has any side to side play in it. I would be very careful and personally I would get the boat looked at and fixed before I ran it again. I would have it checked out by an expert.

Chine walk is when the boat rocks right and left (side to side) underway on the boats chines. Your problem does not sound like chine walk to me

You for sure need hydro steering. Next step would be imco shorty outdrive..

i just put on singel full hydraulic steering from imco, I found it to be good quality and a good price. best bang for the buck.
Can't wait to try it out.

I agree with you,

Get it fixed Jack. Probably wore out steering arm on gimbal. Hyd steering is a must on a small fast boat....ask me how I know

X2 Steering is a must I couldnt imagine trying to hold onto mine with out dual steering

..

Tighten up the two nuts you can see at the top of the drive pivot. Chances are you have a worn steering pin & that will take a repair.
I would at minimum recommend an add-on hydraulic steering system.
I had a 226es (240 Sport) that came with an HP465 (Think HP500) The boat ran really well for speed, but it had a violent tendency. When I would roll off the throttle quickly, the boat would hook to the right. It hooked hard! When I put on the steering it helped, but did not eliminate this issue.
The 240 sport is a fun boat, but it really needs some help in the handling department to make it less dangerous.