Two things....

Anyone with Stinger with Cobra's that had trouble shifting out of gear????

Second, I have stock SBC's turning 14 1/2 21".....i top out at 58 on GPS......problem is at cruise if I bring the drives up any it immediately starts to porpoise.....any suggestions?????

1) there is something called an Electronic Shift Assist Module.

(ESA) this needs to be working or you can damage the drive really quickly.

It operates by killing every other cylinder when you shift, then lights them back up again when you get into/out of gear. If they are working correctly the engine will falter, almost stall when you shift. (But not actually stall).

They are about 100.00 each. They are located on a bracket on top of the intake manifold. It is angled toward the distributor, on the right hand side facing the front of the engine. There is a metal guard partially covering a black plastic box. The black plastic box is the ESA module. It connects via plugs. Two bolts.

Porpoising.
Welcome to the 260Stinger.

You can't be in calm water and also be going full speed and also trimmed out all the way. You will start bouncing like a ball.

It will cost you a mile an hour or two, but in very flat water at very high speed you need to tuck the drives a little or drag a little trim tab.

It's a downside.

Upside is that the boat has a really nice ride.
(It's not a raceboat.)

I saw the micro-switch for the shift assistance. You can push the switch in and retard the engine. The trouble is when you shift the bracket is not moving.....any tips? Everything looked ok on the cable.....it moves a little just not enough to engage the micro switch......If the motor is off you can move the shofter effortlessly. If the module is bad will that only be prevalent when the motor is running? I appreciate the info!!!!! This really is a great first twin boat.....I am looking forward to getting to know it.

i second that! . . .i re-named my boat flipper it seems to be the worst in smooth water.

Well, not trying to be a smart azz, but if it's function is to make every other cylinder stumble, and your boat isn't actually running... how can it work? It works when the boats is running. The micro switch is supposed to work when you shift. Something sounds funny.

No, all I was saying was that I noticed that it moves freely when the motor is not running so I know that it isn't a bind in my shift cable. What will cause it not to move or not move enough to enable the switch is what I am getting at? What adjustment needs to be made on that linkage to get it to move???? Like I said this is an awesome boat and this is really the only problem I have....

I will check my shop book for you.

Even though mine has been modified with an electronic actuator at the helm, the book would address the stock version that you have.

I'll let you know what I find.

Thanks! I really appreciate it!

The ESA works off of two micro switches. As the shift cable is moved the cam that activates the switches is supposed to swing, this activates the first switch and starts the engine stumbling. Then as the shifter moves through it's arc the other switch will engage to stop the ESA from stumbling the engine. I suspect the cam may be binding and not activating the switches. Make sure the cam is free and lubricated and that the first switch makes it stumble and the second switch stops it while the first switch is still pressed. Note-also check that someone has not added on an electronic ignition upgrade-the ESA will not be effective with an electronic ignition.

Finally got to check the book.
Nothing to add to what Ted said.

I can get you a part number for the shop book if you want to try to find one.