Shifting

[manifishdestiny]

Hey All. I was out in the bay last week and after four hours of fishing on the 86 290 TM with twin inboard merc. I tried shifting the port engine into reverse and the engine cut off. When trying to restart port engine it would only start when the shifter was in forward gear rather than neutral as always which I believe is a safety feature.  So needless to say I could come into the harbor in forward but could only reverse with the starboard engine which made for a tricky set-up into the slip.  Any help or past discussions on this topic would be greatly appreciated! Thanks

Anthony

[seabob4]

Anthony,
You have Morse Type S shift and throttles, I presume.

The "start in forward gear" issue would stem from the neutral safety switch inside the shift binnacle.  There is a micro-switch in the binnacle for each shift lever, pull the binnacle and see what's going on with that.  In N, the shift butterfly depresses the lever on top of the switch, closing the start circuit, allowing you to start the motor.  The switch is held in place by 2 screws.  If one has backed out, that could cause the switch to change positions, which may mean that the butterfly is closing the circuit while the lever is in the F position...

But that doesn't explain the engine getting killed when you shift into reverse.  Killing the motor is a function of the kill switch, whereby the coils are grounded, just like shutting the motor down with the key switch.

But I'm thinking both issues are related to neutral safety...

[flounderpounder225]

Sounds like the interlock ignition cut out switch on the engine, on the shift linkage near the carb, a micro switch to momentarily kill the engine when shifting from FWD to rev.  That's my bet

[manifishdestiny]

Thanks. I am going to give those ideas a try today. I am wondering if these parts can still be purchased and how expensive it will be. Thanks again.

Anthony

[Aswaff400]

your boat has a tower? i wonder if there is a neutral safety switch in the upper controls? have you tried shifting/starting from up there? could be something simple like the cables needing adjusting.

the motor dieing when being shifted into reverse says its shift interrupt switch, but if it where that the motor would die trying to shift in to any gear.  i know with Mercuriser I/O's if the motor dies when shifting in/out of gear it means there is resistance in the shift cables to the outdrive so then they need to be replaced...

look between the exhaust riser and the carb, usually starboard side or towards the rear of the motor, is this thing with 2 cables attached?(or somthing similar)

[seabob4]

IIRC, doesn't the shift interrupter switch retard the timing such that he engine "stumbles" when going in and out of gear?  I mean, it should NOT kill the motor...

[Aswaff400]

IIRC, doesn't the shift interrupter switch retard the timing such that he engine "stumbles" when going in and out of gear?  I mean, it should NOT kill the motor...

it cuts the spark for a split second(not noticeable) to allow for a shift, if there is resistance in the shift cable, it will cause the switch to move too far for too long and kill the motor, and if you simply just remove the switch and bypass it, you'll be able to go from neutral to forward OR neutral to reverse but you will not be able to go back to neutral as the transmission/gears are under a load. we had that issue on both our motors at the same time towards the end of a long weekend. talk about difficult time docking

if the cables are original from 1986, im leaning towards those being the culprit

[seabob4]

Aaron,
What you said makes sense in regards to both the issues.  In effect, the shift interrupter switch is mimicking the kill switch, applying a ground to the coils.  Momentarily, a "stumble"...long enough, engine shuts off.  Also, a "stretched" cable will mean a longer throw before the cable actually moves and engages the neutral safety in the binnacle...

New cables, Anthony...and don't tell us you just swapped them out last year!!

Teleflex XTreme universals...  

[wingtime]

I noticed when I had my boat out yesterday it was acting weird while shifting.  If seemed to shift OK but the system check would beep and run a self test when I shifted.  Also my idle would shoot up a bit out of gear and then settle down after a bit.

[manifishdestiny]

Thank you. So far I have had no luck. I will probably have to replace the cables as suggested. I am not sure of the age of the cables so it may be the best idea to replace completely. Is this a diffiicult job? Also if I do not want to use the tower helm how do I disconnect? Thanks.

[seabob4]

Thank you. So far I have had no luck. I will probably have to replace the cables as suggested. I am not sure of the age of the cables so it may be the best idea to replace completely. Is this a diffiicult job? Also if I do not want to use the tower helm how do I disconnect? Thanks.

Anthony,
Not a difficult job, but you'll want as good of access as you ban get to get behind the lower helm.  You may have to remove a b/head in the cabin or a side panel in the wing.  Detach the cable from both the binnacle and engine end, then use that cable to pull the new one.  But two things first.  One, after it's detached, move it back and forth to see if it moves relatively free.  It would be a beetch to have it snag somewhere in the middle of the pull.  Second, assuming they are Morse cables (usually are), there should be a P/N at one end of the cable.  The last 3 digits of the P/N are the cable length in inches.  If per chance they are Teleflex cables, the last 2 numbers are the cable length in feet.  This will tell you what length the new cables should be so you order the right ones.

As far as disabling the upper station, simply remove the cables coming down from the upper station from the lower station binnacles, both shift and throttle.  You'll probably find that this improves the feel of your shift and throttle levers as they are no longer trying to move the upper station levers as well.  But are you sure you want to disable the upper helm?  I wouldn't want to lose the ability to operate the boat from up there...

[manifishdestiny]

I believe I have located the problem. Now I need help to identify the part so that it can be replaced. It is a bolt on part (brass I believe) at the top of the transmission with two male part prongs coming out the top. Their is a black wire that used to be attached but the male parts have broken off. I believe this to be the problem because when I touched the wire to the broken male part the engine started in neutral and shifted to forward to reverse fine. When I removed the wire it started in forward and cut out in reverse with no neutral.  Again thanks for all the help.  

Anthony

[manifishdestiny]

Here is a link for a picture of the part.


http://i.picresize.com/3Dm

[seabob4]

Good deducing, Anthony!  Now, it's on the tranny.  So what make of tranny?  Hurth?  ZF?  Borg-Warner?

[manifishdestiny]

Good deducing, Anthony!  Now, it's on the tranny.  So what make of tranny?  Hurth?  ZF?  Borg-Warner?

Unfortunately I do not know the make. How could I find this out?