Hi,
I am slowly getting my Chriscraft Stinger 202 together. The Big question is the shift assist. This Boat was a basket case I have boxes of parts. Anyways I was wanting to install a MSD marine ignition system into my boat. I will probably be building a whole new harness from start, since I think the old stuff is a pretty big hack job.

So can I get away from having to use the stock shift asist box? What all does this thing do?

I know on some of my bikes, the micro switch was adjusted to cut ignition power for a brief moment just as the shift lever moved enough cause the gear shift. I assume this is doing something similar.

It has been a while for me, but I will give it my best shot. The shift assist disrupts the ignition, but does not kill it completely. I am assuming that you probably have an 80’s vintage Cobra outdrive. It is fairly important that you lower the engine torque during the shifting process. One of the quick ways to tell that the shift assist module was failed is that it is nearly impossible to get the outdrive out of gear without shutting off the engine. If you continually force it, you will stretch the shift cable and eventually the drive will be damaged due to the shift linkage misalignment and the drive not going fully into gear. The symptom of this is that the outdrive will bang out of gear as you try to accelerate. DO NOT ALLOW THIS! CHANGE THE SHIFT CABLE EMEDIATELY!!!. I had Mercruiser prior to the Cobra and Mercruiser’s approach was to have the shift micro switch simply short out the ignition coil. OMC would have almost an identical shift micro switch assembly, but it is used to activate the shift assist module. After several frustrating failures of the shift assist module, I simply rewired the shift micro switch to short out the ignition coil. You will need to verify that the new ignition system can be disrupted during the shifting process. You can use the shift micro switch directly, but the new ignition has to be able to be disrupted to lower the torque for proper shifting.

I hope this helps,

Andy

I had an '86 Cobra system. I had issues with the interrupter switches (which is what they are called). There are 2 of them, the service manual had testing methods for them. One of mine were working intermittently, and left me stranded a couple of times.

I would stay away from those little boogers and figure out your own system. I had a carbed V-6, so I just adjusted the idle as low as I could and removed them all together, and never noticed any difference in engagement going into gear. I guess it depends on your idle and torque, whether you could eliminate them or not, and they won't function with an electronic ignition system anyway, breaker points only.