Merc 140 wont go forward, only backward?

[SSTKO81]

Where to start???? Ok so when launching off the trailer, she started almost right away. I let her warm to just over 100* (according to the thermometer on the dash) at around 700 rpm or so; then went to put it in gear. I've always been told, dont do it slow, just pull it back till you feel it kick in. -so i did, and it died. and it died and it died. After 4-5 tries I goosed the throttle to 1500 RPM and jerked it quick into reverse. It tried to die but recovered and I got off the trailer put it in neutral and all's well. Then I shifted to drive and died. and died and died. Again after 4-5 tries I goosed the throttle up to 1500 RPM or so and dumped it quick into Drive (yes, i know... shouldn't do that) but it stayed running. I idled out of the cove at 1000 rmp or so and finally gave it gas. -got up on plane and ran great at WOT 4200 RPM. Reached a fishing spot and slowed to idle and it died. This time it was VERY difficult to start, taking 8 tries or more and when it did, absolutely would not go into drive. -it would go in reverse though. So i had to back up about a mile to the dock. I never could get it to move in drive. It died every time. I was told it may be a fuel issue? I was also told it may be a shift cut-out issue? Ever seen this before?

 

[Bt Doctur]

Re: Merc 140 wont go forward, only backward?

most likely a lower shift cable

 

[achris]

Re: Merc 140 wont go forward, only backward?

...Ever seen this before?

Too many times to count.... Sticky lower shift cable or gummed up upper shift shaft, caused by a water leak into the shift slide cavity.

Have a read of this thread (in the Sitckies) and all will be revealed...

HOW TO: How the Shift Interrupt system works

 

[SSTKO81]

Re: Merc 140 wont go forward, only backward?

Too many times to count.... Sticky lower shift cable or gummed up upper shift shaft, caused by a water leak into the shift slide cavity.

Have a read of this thread (in the Sitckies) and all will be revealed...

HOW TO: How the Shift Interrupt system works

Understood... so realistically what are we talking about as far as difficulty to replace either or both of these parts?
Is it easy to get too? I've done a ton of work on this engine and boat, but as far as the shift linkages and electronics I'm still a frosh. I really appreciate the help guys

 

[sptjet90Reflexx]

Re: Merc 140 wont go forward, only backward?

ignore this

 

[SSTKO81]

Re: Merc 140 wont go forward, only backward?

Moreover, I have noticed the throttle is a little "sticky" kinda tough to push fwd or reverse... But all the linkages to the carb seem good and smooth. Related?

 

[dubs283]

Re: Merc 140 wont go forward, only backward?

start with the lower shift cable, that should alleviate your intial issue

if you still notice a stiff shift, check the remote cable(s)

 

[Bondo]

Re: Merc 140 wont go forward, only backward?

Understood... so realistically what are we talking about as far as difficulty to replace either or both of these parts?
Is it easy to get too? I've done a ton of work on this engine and boat, but as far as the shift linkages and electronics I'm still a frosh. I really appreciate the help guys

Ayuh,.... It's probably an 8 of 10 in difficulty,...

If doin' the lower shift cable, I'd do All the rubber parts in the transom at the same time,...

Do a search, 'n look in the Adults Only section to see what yer up against...

 

[SSTKO81]

Re: Merc 140 wont go forward, only backward?

Ayuh,.... It's probably an 8 of 10 in difficulty,...

If doin' the lower shift cable, I'd do All the rubber parts in the transom at the same time,...

Do a search, 'n look in the Adults Only section to see what yer up against...

Went out this weekend to check things out... Found that when moving the shifter forward or back the cam that opens and closes the shift interrupter wasn't moving at all. But the lower shift cable is moving freely. Just kinda looks like there's excessive play or it's loose. -weird tho cause I've never touched that part of the cables. Only messed with throttle cable around carb. That wouldn't throw it out of whack would it?

 

[dubs283]

Re: Merc 140 wont go forward, only backward?

Found that when moving the shifter forward or back the cam that opens and closes the shift interrupter wasn't moving at all.

if the engine isnt running with the boat in the water the shift interrupt system wont operate

there needs to be a load on the prop to engage the shift interrupt

this is why people will say "on the muffs on dry land the drive shifts perfect but when i back it in the water the engine dies every time i shift"

your problem most likely is the lower shift cable binding, it needs to be replaced

 

[Bondo]

Re: Merc 140 wont go forward, only backward?

Went out this weekend to check things out... Found that when moving the shifter forward or back the cam that opens and closes the shift interrupter wasn't moving at all. But the lower shift cable is moving freely. Just kinda looks like there's excessive play or it's loose. -weird tho cause I've never touched that part of the cables. Only messed with throttle cable around carb. That wouldn't throw it out of whack would it?

Ayuh,... The Inner cable wears a groove in the Outer cable, causin' slop,...

Replacin' the lower cable is the cure...

 

[SSTKO81]

Re: Merc 140 wont go forward, only backward?

Ayuh,... The Inner cable wears a groove in the Outer cable, causin' slop,...

Replacin' the lower cable is the cure...

ok, so thats that. Then Step 1 pull the drive, pull the bellows, pull the cables and get cracking
Actually that's 3 steps but still gonna be a lot of work

 

[SSTKO81]

Re: Merc 140 wont go forward, only backward?

ok, so thats that. Then Step 1 pull the drive, pull the bellows, pull the cables and get cracking
Actually that's 3 steps but still gonna be a lot of work

Survey says...
I found the shift cable to be melted through from sitting against the oil pan. This caused the inner cable to bind, thus, it died every time I put in gear.
Replaced all bellows w/ the shift cable and everything is nice and smooth and works great! Thanks guys.

 

[SSTKO81]

AND A YEAR LATER PULLED THE ENGINE; MOUNT CAUGHT ON THE CABLE, PUT A KINK IN IT AND IT WONT SHIFT INTO REVERSE... MULLIGAN

 

[Bt Doctur]

A good trick considering the cable is nowhere the pan to begin with

 

[SSTKO81]

The cable comes in through the transom just under the coupler then runs up behind the exhaust pipe to connect to the upper shift cable connection block. It a short distance but a fairly long cable. So yes, it used to rub on the bottom side of the oil pan, which is what caused it initial failure.

 

[Bt Doctur]

see page 75 in here http://www.boatfix.com/merc/Install/gas/86016900.pdf

 

[SSTKO81]

Appreciate the PDFs those will be helpful in the future.