The shift interrupt should Not cut out the ignition if the cable is in
good working order AND adjusted correctly. The purpose of the interrupt
switch is to prevent damage to the drive from the throttle opening
before forward or reverse gear is engaged. A number of models did not
come supplied with interrupters at all. I would check the adjustment,
if incorrect, adjust to spec, if still sticking then check the lower
shif cable. You can sometimes see dried mineral deposits directly under
the engine end of the lower cable, indicating a leaky shift bellows and
probable damage to the cable, it only takes a few ounces of extra
resistance to cause a problem, but if you do have a shift interrupt
switch ,the engine will stall when shifting(as it should to prevent
damage.)..Also make sure your idle speed is correct...
markvictor

The shift bellow doesn't seal water out of the cable. If the bellow leaks
the boat will take on water. A defective shift shaft bushing is the main
cause for water intrusion into the shift cable. An inoperable interrupter
may be causing difficulty pulling out of gear and inadvertantly shifting
into the opposite gear. Idle speed too high will cause this as well but the
shift clunk will be unusually loud. If the throttle opens too soon, your
cables need adjusting. If the engine stalls while shifting there is
excessive resistance in the lower cable or linkages.
Jim

"markvictor" wrote in message
oups.com...
The shift interrupt should Not cut out the ignition if the cable is in
good working order AND adjusted correctly. The purpose of the interrupt
switch is to prevent damage to the drive from the throttle opening
before forward or reverse gear is engaged. A number of models did not
come supplied with interrupters at all. I would check the adjustment,
if incorrect, adjust to spec, if still sticking then check the lower
shif cable. You can sometimes see dried mineral deposits directly under
the engine end of the lower cable, indicating a leaky shift bellows and
probable damage to the cable, it only takes a few ounces of extra
resistance to cause a problem, but if you do have a shift interrupt
switch ,the engine will stall when shifting(as it should to prevent
damage.)..Also make sure your idle speed is correct...
markvictor

"markvictor" wrote in message
oups.com...
The shift interrupt should Not cut out the ignition if the cable is in
good working order AND adjusted correctly. The purpose of the interrupt
switch is to prevent damage to the drive from the throttle opening
before forward or reverse gear is engaged. A number of models did not
come supplied with interrupters at all. I would check the adjustment,
if incorrect, adjust to spec, if still sticking then check the lower
shif cable. You can sometimes see dried mineral deposits directly under
the engine end of the lower cable, indicating a leaky shift bellows and
probable damage to the cable, it only takes a few ounces of extra
resistance to cause a problem, but if you do have a shift interrupt
switch ,the engine will stall when shifting(as it should to prevent
damage.)..Also make sure your idle speed is correct...
markvictor


All correct except the shift engine kill switch SHOULD engage if there is
any resistance disengaging from reverse or forward into neutral. This
resistance (if shift cable is good) comes from the dog gear not disengaging
because the engine is running faster than the prop. The kill switch engages
and the motor slows relative to the prop and the gear can disengage.

Jeff Rigby wrote:

All correct except the shift engine kill switch SHOULD engage if there is
any resistance disengaging from reverse or forward into neutral.

I agree, but when the control cable and lower shift cable are in good
condition, and adjusted correctly, the only way the clutch is "loaded",
is essentially when underway above nominal idle,or excessive rpms prior
to shifting, thus keeping tension on the clutch dogs.



if the cables are out of adjustment, When trying to engage
from neutral, if the rpm's are too high from premature throttle
opening,the clutch will resist and the interrupt switch is actuated.
When in gear,if the throttle is not closed and rhe RPM's are ,once
again, higher than nominal idle speed, the clutch dogs resist
disengagement, again tripping the interrupt switch...



This resistance (if shift cable is good) comes from the dog gear not disengaging
because the engine is running faster than the prop. The kill switch engages
and the motor slows relative to the prop and the gear can disengage.


If the engine is running, and the drive is engaged (in gear) It is
absolutely impossible for the engine to EVER run slower than the
propshaft...Alpha ratios (1.50 1.62, 1.81, 2.00, etc..) are all greater
than 1. This means that with a 1.50 to 1 gear ratio, the engine is
turning one and a half turns for every one turn of the propshaft...so
at 1500 tach rpm, the shaft is turning 1000rpm...at 3000 tach rpm, the
propshaft turns at 2000 rpm...at 600 tach rpm the shaft turns at 400
rpm,...at 150 tach rpm, the shaft would turn at 100 rpm aand so on,till
the engine is at a dead stop. A momentary spark interruption does not
stop the engine. If you try to do full throttle direction changes, the
interrupter should move to prevent damage, but in normal operation, the
throttle hits the stop before the shift action proceeds, and the
decelleration of the motor unloads the clutch dogs, and if the boat is
moving, the flow of water over the prop actually aids in unloading
it....Bottom line, the two causes of interrupter activation is
attempting high load shifts, either from too rapid shifting at high rpm
or misadjusted cables, or a simulated shift load caused by resistance
from a damaged cable or possibly a heavily worn selector shaft bushing
and seal.

wrote:
When the boat is in the water and I
switch the gear shift to neutral, it will NOT go into neutral most of
the time...it just stays at the "no wake" speed but the shifter is in
neutral. I have to shift it back and forth to get it to finally go to
neutral. Any help would be greatly appreciated.

The fact that the control handle is in the neutral position but the
clutch is still engaged, is a pretty clear indication that there is not
enough throw on the lower cable. This is often caused by the cable end
on the interrupter bracket being positioned incorrectly in the slot on
the cantilever.. On the v8's and v6's it should be at the bottom of the
slot, but if memory serves me correctly, the 4 cyl. plate is inverted
and the cable should be at the top of the slot. That will increase
throw on the lower cable, and minimize or eliminate any unnecessary
movement of the switch. If it was a bad cable, or high rpms, it would
stall the motor while hunting back and forth to find neutral

trainfan1 wrote:

Yes, it should... not entirely, just enough to shake the clutch dog off
the gear

No, it shouldn't, unless something is wrong...or you're shifting
improperly, such as lock to lock..

Different adjustment.

Of course it is, it's the throttle cable, but that can cause premature
opening of the throttle plate, which in turn causes rpms to increase
prior to gear engagement,which causes increased effort tho engage the
clutch dogs,which should cause the interrupter. to actuate, which
causes the boat to stall, etc etc,...But that's what's supposed to
happen if the throttle opens too soon....

Jeff Rigby wrote:
Probably the shifter cable is bad, your shifter kill switch is not engaging.

That is when it would engage, if the cable was bad

The engine has to be moving slower than
the prop for the gear to go into neutral thus the kill switch. (In the water
because of the inertia of the water the prop is always going to be running
slower than the engine unless the kill switch is working.)

I repeat, as long as the drive gear is engaged the engine will turn
faster than the propshaft,
it's a positive engagement clutch, ans a fixed ratio...there can be no
change of one without the same proportional change of the other until
AFTER disengagement occurs, not before...

JIMinFL wrote:
The shift bellow doesn't seal water out of the cable. If the bellow leaks
the boat will take on water. A defective shift shaft bushing is the main
cause for water intrusion into the shift cable

You're absolutely right,,,

markvictor wrote:
Jeff Rigby wrote:


All correct except the shift engine kill switch SHOULD engage if there is
any resistance disengaging from reverse or forward into neutral.


I agree, but when the control cable and lower shift cable are in good
condition, and adjusted correctly, the only way the clutch is "loaded",
is essentially when underway above nominal idle,or excessive rpms prior
to shifting, thus keeping tension on the clutch dogs.

markvictor, you're confusing yourself immensley.

Brand new Alpha. Disconnect the interrupter. Guess what? It wont come
out of gear, even at idle(in water, under way), unless you use the cable
and pull the shift lever past neutral into reverse... then guess what?
you're in reverse! From neutral, it'll go INTO gear all day long no
matter how fast you shift & throttle(& actually, the faster you shift
the better for the dog & gears in the foot - none of that
chunka-chunka-chunka-chunka-clunk stuff...).

Makes docking tough.

Connect the interrupter. Shifts like a dream(at least as good as a dog
clutch leg can)!

Rob

It's not a brand new alpha, it'a a 7 year old carbureted 4 cyl.. but I
do agree that an answer as to shifting effort would help diagnosis...

sorry guys..down with a cold for a few days. Thanks for all the
replies.

I have no physical difficulty putting it in and out of gear, the
process is actually quite smooth. Occasionally, I do hear the shift
interupter cut the engine for 1/2 second when I take it out of gear.
The engine speed is idled correctly in my opinion...in neutral-on land
it usually tach's at 1200-1500 rpm
Also, when on land and I put it in fwd, I hear gear grinding for 1/2
sec...kinda like I power shifted a car without pushing in the clutch.
I just bought the boat used about 2 months ago and the guy I bought it
from had used it in salt water.

I do not have the manual nor have I ever worked on a boat so have no
idea where the interupter...I guess I get to learn the old fashion
way....by looking for it. anyone have any schematics they can throw my
way.
Trying to prevent from going to a merc dealer....or should i just bite
the bullet?
ps - it is a carb engine
Thank you all again

wrote in message
oups.com...
sorry guys..down with a cold for a few days. Thanks for all the
replies.

I have no physical difficulty putting it in and out of gear, the
process is actually quite smooth. Occasionally, I do hear the shift
interupter cut the engine for 1/2 second when I take it out of gear.
The engine speed is idled correctly in my opinion...in neutral-on land
it usually tach's at 1200-1500 rpm


Way too high. What engine? Idle in neutral, depending on engine, should
be close to 600 RPM if I recall correctly.

Eisboch

EFI? brand new alpha? are you in base timing mode?

markvictor wrote:
EFI? brand new alpha? are you in base timing mode?


Who are you responding to? What are you responding to? Who said EFI?

You're confusing yourself immensley.

Take for example a brand new Alpha 135. Disconnect the interrupter.
Guess what? It wont come out of gear, even at idle(in water, under
way), unless you use the cable and pull the shift lever past neutral
into reverse... then guess what? you're in reverse! From neutral, it'll
go INTO gear all day long no matter how fast you shift & throttle(&
actually, the faster you shift the better for the dog & gears in the
foot - none of that chunka-chunka-chunka-chunka-clunk stuff...).

Makes docking tough.

Now connect the interrupter on our EXAMPLE brand new Alpha 135. Shifts
like a dream(at least as good as a dog clutch leg can)!

You obviously do not understand the need for an interrupter on the Alpha
leg. (135hp is a carb engine)

It's for getting out of gear, in water. Engine running. Period.

Not running, or on the flush muffs, you don't need the interrupter, in
fact it shouldn't even activate... it's action is based on the force
needed to overcome the resistance of a drive working against the water,
the ratcheted clutch dog teeth embedded into the drive gear, which is
the exact problem the OP has.

Now he's telling us the idle is twice as high as it should be, which
compounds the problem - even more force demanded of that lower shift
cable. Without the interrupter, he's headed for a docking, trailering,
or maneuvering disaster.

Rob