Alpha-1 MR: Dificult shifting from F/R back into Neutral

[mylesm260]

Alpha 1-MR

Brand new shift cable, bellows, and lots of other parts.


If I have my engine running in my driveway (with the ear-muffs on), I can shift from neutral, into gear, and easily shift back.


However, if I'm in the water, I can shift from neutral to drive no problem, but if I try to shift back into neutral, my shifter feels like it's "binding" and it doesn't want to go, if I shut the engine off, shift it into neutral, and fire the engine back up, it's fine.


I had this problem before I changed my shift cable and bellows, and I thought that changing them would solve the problem, unfortunatly it hasn't.


I read something somewhere about mercury putting the wrong part in the lower drive assembley in certain years, I believe my drive is an 85'.

I've also had the drive off once already since I put the new cable and bellows in, and there was no water in the shift cable assembly.

I also verified that there is oil in the drive, and there is, the oil is green, and not milky (I only have about 1 hour on this boat since I put it back together with new bellows and a new shift-shaft.

 

[JustJason]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

if its a new cable...... check to make sure the shift cut out switch is working by manually flipping it. also check the routing of the cable, there should be no serious bends.
when you installed the new cable, did you make sure that the nut on the cable end screwed all the way down into the bellhousing, with no more than 2 threads exposed?

 

[Bondo]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

check to make sure the shift cut out switch is working by manually flipping it.

Ayuh,..... That's My Guess...

 

[JustJason]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

actually one more thing...
what are your idle rpms??
to high an idle will cause that to

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

Shift cable is installed properly, I believe. Used the special socket to tighten the nut all the way into the bell-housing. I routed it the lazy way around on the port side, there are no sudden turns.

I am running the automotive chevy fuel injection with computer controlled idle. My idle is ALWAYS 650, (unless the engine is cold and warming up).

Now, the "shift cut out switch" I have no idea what this is, and I may have disabled this during my automotive re-power.

I have a switch in my shift assembly that does not allow me to start while I'm in gear, is this what you are refering to?

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

Okay, someone please just confirm if I've figured this out.

Does the "shift cut out switch" temporarily cause your engine to slow down as you shift from gear back into neutral?

I'm guessing it's wired in series with the power to the ignition coil? that way as you pass through it's threshold, you engine will "stutter" and take the load off the lower gears and allow them to shift more smoothly?


When I re-powered, I asumed it was a safety switch to prevent the engine from starting in gear, my boat has a newer shift/throttle assembly up front, and it apears to take care of that, so I thought it was redundant and never bothered re-connecting it.

 

[Bondo]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

Does the "shift cut out switch" temporarily cause your engine to slow down as you shift from gear back into neutral?

I'm guessing it's wired in series with the power to the ignition coil? that way as you pass through it's threshold, you engine will "stutter" and take the load off the lower gears and allow them to shift more smoothly?

Ayuh,... That's Correct....

It's supposed to work, Only coming Out of Gear,+ Only with a load on the prop...

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

How does it know if there is a load on the prop?


Also, to make sure I'm talking about the right switch, is it the one on the shift lever assembley on the starbord manifold, where the shift cable from the shift/throttle controls connect with the lower shift cable?

 

[Bondo]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

Also, to make sure I'm talking about the right switch, is it the one on the shift lever assembley on the starbord manifold, where the shift cable from the shift/throttle controls connect with the lower shift cable?

YES......

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

Sweet!

That's one problem solved.

Thank you both very very much!

Now if I could only figure out this damn drive/spline shaft issue, I'd be set!

 

[Fishermark]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

I am running the automotive chevy fuel injection with computer controlled idle.

Did you simply drop an automobile engine and fuel system in the boat? What about the starter, alternator, fuel pumps, etc? Are they automotive or marine?

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

alternator and starter are marine.

Fuel pump is automotive (but high pressure sealed EFI)

I also run with my engine bay blower on all the time.


My fuel lines are all braided (stainless) steel EFI hose.


Good thing about EFI vs carb in terms of marine safety is this.

In a carbed system you can have a fuel leak and not know it at all
If you have a fuel leak in EFI, your engine dies instantly, you need your rail pressure to keep the engine running. With a carb you have a float that can keep the engine running long after you run into a fuel leak problem.

 

[WizeOne]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

How did you get around the O2 sensor?

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

The vortec's are MAF based. That means they measure the air as it enters the engine.

O2 sensors are much less important in this setup.

If I connect my OBD-2 code reader to the ECU, I get a code for the 02 sensor.

Having said that, half the cars on the road are running with dead-o2 sensors, The ECU just goes into "open loop" mode.


Hondas for example run MAP based systems, in those setups, o2 sensors are much more important.

Even without the o2 sensor, I still get fanstatic fuel economy.

I changed from a 17 to a 23 pitched prop, and now I can top out at 65 MPH (GPS verified) where my old carbed 4.3 had trouble reaching 50.

Also, I can do 35 MPH at 2900 RPMS, excelent crusing economy.

The EFI vortec has a very very good bottom end torque compaired to a carbed motor. even with the bigger prop, I get on plane in about the same amount of time as the carbed motor did with 17 pitched.


Also, if you look at the mercruiser specs for the marine 4.3, it's the exact same internals and cam as the automotive vortec. In the AWD van it came out of, it was rated for 200 HP, in the boat it's rated for 238 because of the lack of exhaust restriction.


It will be a nice setup once I get the kinks worked out, I have a feeling I know what I need to do now.

The EFI setup I have is 10 times better than my old carbed setup.

Just the computer controlled idle alone is heavenly, no stalling, no worring about adjusting the idle.

If I'm in neutral, 650 RPMS, if I'm in gear, 650 rpms, never need to worry about a thing.

 

[mylesm260]

Re: Alpha-1 MR: Dificult shifting from F/R back into Neutral

Thanks for your help guys,

Because of my EFI, I had to wire up an ignition kill relay.
The shift interupt switch triggers the relay, which breaks power to the coil and causes my engine to stutter just enough to slide out of gear.

And I understand now how it knows if the engine is under load (spring on shift cable)