Shift Interrupt Switch Help
#1
Thread Starter
Registered

Joined: Sep 2013
Posts: 696
Likes: 111
From: KY
Took my 26’ Firehawk cat out yesterday for the first time. I posted another thread about my steering issue. On top of my steering issue, I’ll be replacing bellows within the next week or so and my drive shifts hard. It’s a blower motor with a big cam so I tried to time my shifting when the RPMs dropped the best I could. Short run to see what issues I needed to address.
So I need help with understanding the shift interrupt switch.
Should I have a switch where the shift cable engages the short drive cable in the bilge(because I do not)? Or can this switch be tied into the shifter (gaffing) at the helm?
At the helm, I looked at the wiring and was able to figure out which wires were for the trim. 3 wires remain, blue, red, and black. Are all 3 of these for the neutral safety? The neutral safety does work.
Anyways, is this as simple as buying a switch and putting it here?

It has a digital 6AL MSD ignition. Not the marine version so it does not have a timing retard wire. So will wiring this switch inline with the coil ground wire be okay? Thanks for the help.
So I need help with understanding the shift interrupt switch.
Should I have a switch where the shift cable engages the short drive cable in the bilge(because I do not)? Or can this switch be tied into the shifter (gaffing) at the helm?
At the helm, I looked at the wiring and was able to figure out which wires were for the trim. 3 wires remain, blue, red, and black. Are all 3 of these for the neutral safety? The neutral safety does work.
Anyways, is this as simple as buying a switch and putting it here?

It has a digital 6AL MSD ignition. Not the marine version so it does not have a timing retard wire. So will wiring this switch inline with the coil ground wire be okay? Thanks for the help.
#3
Thread Starter
Registered

Joined: Sep 2013
Posts: 696
Likes: 111
From: KY
I didn’t like the sound or feel at all when shifting into reverse, even timing it with the rpm drop which was below 700.
If I did install a switch, would it help?
#6
Thread Starter
Registered

Joined: Sep 2013
Posts: 696
Likes: 111
From: KY
#7
Registered

Joined: Jan 2007
Posts: 2,104
Likes: 1,224
From: Murrayville Georgia
what you feel is the cone clutch engaging. it is what it is unless there is a problem with lots of wear on the clutch. most bravos thump when they go in as the clutch is drawn up into the cone. if you want a smooth shift you would have to ditch the bravo and put a speedmaster on it with a transmission which is not practical for your boat.
#8
Thread Starter
Registered

Joined: Sep 2013
Posts: 696
Likes: 111
From: KY
what you feel is the cone clutch engaging. it is what it is unless there is a problem with lots of wear on the clutch. most bravos thump when they go in as the clutch is drawn up into the cone. if you want a smooth shift you would have to ditch the bravo and put a speedmaster on it with a transmission which is not practical for your boat.
#9
Registered

Joined: Nov 2004
Posts: 14,181
Likes: 3,734
From: On A Dirt Floor
Yes, there is an answer for help.
The Daytona Marine ignition boxes are fully programable and have an idle stabilization feature for helping issues like yours.
several peeps on this board have successfully used them on sc’d applications. ICDEDPPL and Mild Thunder are two. They have many write ups on them
The Daytona Marine ignition boxes are fully programable and have an idle stabilization feature for helping issues like yours.
several peeps on this board have successfully used them on sc’d applications. ICDEDPPL and Mild Thunder are two. They have many write ups on them
Last edited by SB; 05-10-2026 at 01:09 PM.
#10
Registered

Joined: Nov 2004
Posts: 14,181
Likes: 3,734
From: On A Dirt Floor


