HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

cjgreene1

Cadet
Joined
May 19, 2012
Messages
11
I have an 81 18' cuddy with the 140 Merc. I have been chasing this problem sense I bought the boat!!!! Runs fine on ground, runs fine in neutral, as soon as its under load in gear in water it will stall at exactly 2000 rpms if I back it off when it starts to stall it will stay running and if it stalls it will start right back up. If I get it over 2000 rpms by babying the throttle (which I always eventually do) it again runs great. Thought it was the accelerator pump as there was a tear in seal at the end of the shaft replaced with no luck. Tank drained, lines replaced, filters replaced, water seperater added, carb cleaned (but not soaked or full rebuild though I was told this was all done 2 seasons ago). Took it out today after the carb clean and accelerator pump replace, put her at wot and it didn't stall at 2000rpms on the way back to the dock problem started again and now back to you guessed it square 1. Last owner said he did have this problem but it was fixed after carb rebuild so I deff think its a carb issue but who knows I have had it at this point and am at a loss PLEASE HELP have seen this problem all over diff forums but no real answers.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

First things I would be doing are.
1. Compression test.
2. New points, rotor, condensor. Set the timing.
3. Check the condition of cap and plug leads. Replace if suspect.
4. Test the coil.
5. With a timing light and the boat in the water, (but only tied to the jetty) check the timing advance.

Only when all these things check out correctly would I start looking at the carburetor... And only then after I had FULLY checked out the rest of the fuel system. Get an outboard style remote fuel tank and run it with that... Make sure you have no air leaks in the fuel lines (air getting sucked in, not fuel being pushed out)...

Chris..........
 

cjgreene1

Cadet
Joined
May 19, 2012
Messages
11
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

Yes I have had a few people tell me to check those things... However, I have receipts for all o those things proving they have been either checked or replaced in the last year by a marina... The reason I keep leaning towards the carb is because the gentleman that sold me the boat has been very helpfull and honest and told me that he had the same problem 3 years ago and the marina rebuilt the carb and The problem was fixed.
 

daydreamer1252

Petty Officer 1st Class
Joined
Aug 7, 2007
Messages
212
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

cjgreene1....not to step in on Chris' reply but....the things he related to you are the correct steps in attempting to diagnose the issue...the whole lot is maybe one afternoon and about $30 to $100 tops....if you would rather believe the "receipts" then just get the carb done.....but don't be surprised if it doesn't just go away.....not wanting to be harsh to you.....remember even the most honest person can be wrong, as similar symptoms can come from different problems.....but it seems that you have made up your mind what the problem is already and are looking for someone's agreement/blessing......seldom will you find that here, but you will find lots of help and suggestions as to how to REALLY find and fix the problem.....hope you find the solution soon...summers wasting.....
:
 

cjgreene1

Cadet
Joined
May 19, 2012
Messages
11
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

I agree with what your saying of "possiblilities" but if that's the case why wouldn't I at least try to clean The carb and jets especially sense 2000 rpm is where a boats carb begins to operate differently just think its too much of a coincidence to overlook that's 5 dollars for a can of cleaner and an hr of tare down ad rebolt. And what your suggesting to start with will be much more then your estimate sense I don't have a timing light, or the tools/know how needed to check the other things. I just think its a little rediculous I'm getting crucified on here for wanting to pull a carb and cleaning it before spending money lol and getting I'm over my head.. But everyone seems to always jump to these crazy and most horrific problems first on this forum if I'm being honest it's almost comical.... I know what COULD be wrong I was asking if anyone's had this problem so I could better pin point it rather then taking shot after shot after shot in the dark which in all honesty has been coming from clowns on this forum.... Already have 300 into it from doing that and still have the problem.... I.e. fuel lines, fuel filter, accelerator pump, anti syphan valve, water sepporater. I am positive it's a fuel issue the only thing left is the carb I appreciate the advice though.
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

I was asking if anyone's had this problem so I could better pin point it rather then taking shot after shot after shot in the dark which in all honesty has been coming from clowns on this forum....


Whoooa there sparky.

You are not going to get much help from the "clowns" on this forum with responses like that....

I'd reply with some helpful info, but have to go out and track down my big shoes, face paint and rubber chicken.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

cjgreene1,

If you are happy and confident that everything else has been checked, then go right ahead and strip the carburetor... If I had the problem, and all the things I listed had been done, then yes, I'd be into the carbie too...

The only reason I mentioned all those things is that in your initial post you never said they'd been done. I was going to mention something else, important, but as a clown it's probably more funny than useful....

Hope it all works out for you...

Your sincerely,

A. Clown... :mad:
 

rick3452

Petty Officer 1st Class
Joined
Oct 26, 2010
Messages
282
Re: HELP TRIED EVERYTHING Merc 140 Stalling at 2000 rpms under load

Clowns?! :facepalm: Stick to the skateboard, you're too young to be messing with boats.....
 
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