Used to be TBI, now Carb, need some ideas on "shift assist".......

[Insanegtp]

Removed 97 Merc 5.7 TBI, Installed 383 Carbed over winter, after a few days of tinkering with carb and timing I think I got it pretty good.... Issue now is it gets stuck in either reverse or forward.. I checked cables, they seem to move freely, I tried adjusting slider a bit in each direction, I seen a slot that looks to increase / decrease throw, played with that, I still need to "jiggle" throttle control to release, I read somwhere that the two wires going to shift bracket assist with lowering engine rpm's or even kill ignition temp to allow the clutch dog to release... anyone ever make this work on an engine setup that wasn't stock ??? ---- I can't be the only one...

 

[Don S]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

Which outdrive do you have Alpha or Bravo ?

I read somwhere that the two wires going to shift bracket assist with lowering engine rpm's or even kill ignition

Do you have the shift interrupt switch ?

 

[Insanegtp]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

Alpha one, and yes the switch with the purple wires connecting to white ?? I think is still there.....

 

[Don S]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

Alpha one, and yes the switch with the purple wires connecting to white ?? I think is still there.....

Are the wires hooked to anything? Can you post pictures of your shift setup?

What distributor are you now using? IF you are using your original EST distributor, do you still have access to the wiring harness so you can use part of it?

 

[Insanegtp]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

The wires are still there and not connected to anything, I cannot get pics right now I am not with boat but do hope to get to it tonight and try a few things... The dist is a MSD 8394 Digital E Curve, it doesnt have the ability to connect to anything else.... all wiring is still in boat...

 

[Don S]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

That is not even a marine distributor.

 

[Insanegtp]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

looking through some manuals I seen on older carbed and even some recent (late 90's) carbed engines the shift interuppter has one wire grounded and the other goes to the negative terminal on the coil, assuming this temp kills ignition so the strain on the clutch is minimized, the momemtum of flywheel keeping the engine spining so it stays running... is this true ??

 

[Don S]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

Yes, the switch shorts the ignition to ground on some (not all). But with that distributor, you could destroy the module in it if you short it.

Why don't you just use the Distributor and coil off your old engine. It's a lot better setup than any MSD I have seen.

 

[Insanegtp]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

the old dist was also an MSD with the module in it.. but I beileve I would have to retain all the computers and that has been eleminated, I gonna call MSD and see if it will break that, I also might see if I can wire a relay to temp kill power to the coil....

 

[Don S]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

the old dist was also an MSD with the module in it..

I some how doubt that, it could not be read by the ECM if it wasn't an EST distributor.

 

[Don S]

Re: Used to be TBI, now Carb, need some ideas on "shift assist".......

http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-119.html

Genuine 5.7L GM Delco Voyager EST marine electronic distributor kit. Made for ALL 5.7L (350ci) marine engines made from 1967-2011 (standard rotation). Excellent replacement kit for older "points" distributor system. This distributor and kit is U.S Coast Guard Approved and has the official marine SAE J1171 stamp on the bottom of the distributor. This is the EXACT kit that MerCruiser, Volvo Penta, OMC, Indmar, PCM, Marine Power, etc use on their 5.7L marine engines.