Mercruiser 140

[Uncle Dave]

1986 model. Conventional ignition Just did complete tune up and carb kit.<br />Runs good and shifts forward and reverse easily.<br />The interrupt swith does not interrupt. During shift the gears gnash quite badly. Not sounding good.<br />The interupt switch works when activated by hand.<br />The Shift plate seems to need to go just a little farther.<br />I have never been into this area before. Any help or suggestions would be appreciated.<br />Uncle Dave

 

[Bt Doctur]

Re: Mercruiser 140

Shift interupter only works coming out of gear.its normal to have the clunk engaging due to the cut of the shift slider and gears.

 

[novicetech]

Re: Mercruiser 140

It is normal for the clunk going into gear and your outdrive will last longer and you will have less noise if it is idled in gear as close to 600 rpms as you can get without the motor stalling.

 

[Bondo]

Re: Mercruiser 140

Shift interupter only works coming out of gear.

And,............ Only when the Prop is IN the Water..............<br />

Runs good and shifts forward and reverse easily.

If this is True,..... The Shift-Interupter is Working,.... Perfectly...........<br /><br />As Stated,....... Alphas Need to be shifted,.. Briskly Into gear...... At a Low Idle.....<br />1 Good Solid Clunk,... Is a Good Thing..........

 

[Uncle Dave]

Re: Mercruiser 140

Thanks all for the inputs. I will not mess with it.<br />However, I did ohm it out with the key swithch off.<br />When you leave idle (starting to shift) the switch closes and stays closed to WOT. Same in reverse.<br />Seems that would interupt the points on a permanemnt basics.<br />Thought about someone chaging the wiring, but manualy operating the micro swith will shut down the engine.<br />Someone once said if it aint broke dont fix it. <br />Just curious I guess.<br /><br />Uncle Dave

 

[Don S]

Re: Mercruiser 140

That's because the engine isn't running and the dog clutch is probably on a high spot. <br />If the shifter works easy when in the water, don't mess with it. Sounds like your trying to find something wrong with something that is working.<br />Do you have a Merc manual?

 

[Uncle Dave]

Re: Mercruiser 140

Good evening Don,<br /><br />You betcha I aint gonna "fix it". Just have never heard the engine stumble (interrupt) while shifting. <br />AND just wanto know how it works. <br /><br />Uncle Dave

 

[Don S]

Re: Mercruiser 140

Out of the water you won't here it stumble, there isn't any pressure on the prop to cause it.<br />Going into gear it won't work unless the cable is bad, the gears and shift dogs have ramps to allow them in without the interrupt system. When coming out of gear (IN THE WATER) there is only a slight difference in engine sound when all is working fine. It's a very slight hesitation that takes the pressure off the dog type clutch with back cut gears. It just takes the pressure of the shift dog, nothing more.

 

[Uncle Dave]

Re: Mercruiser 140

Thanks, and I will leave it alone.<br />UD

 

[achris]

Re: Mercruiser 140

For a description of the operation of the shift interruper see this link.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000029