I have a 125 force outboard idles great and at low

FAILS HOT ENGINE OR COLD OR BOTH???????
FIRST OFF 600 RPM IS DEAD WRONG
800 IS NORMAL HOT,
IF HOT NORMAL ENGINE SHOWS NOT REGULATING RPM BUT VARIES THAT MEANS THE PCM HAS LOST CONTROL OF IDLE SPEED.!!!
YES PCM JOB IS THIS AND USA BY EPA LAWS TOO.
ALSO PUT IN NEW OIL.
SEEMS TO ME YOUR GARAGE IS NOT VERY WISE. OR SKILLED, FIND AND ASE SHOP.

OUR CARS HERE THE THROTTLE BODY HAS
TWB , THROTTLE BY WIRE, AND PCM RUNS THE MOTOR THERE FULL TIME TO HOLD SPEC, RPM AT IDLE
IS CAR A/T M/T BOX? AUTO OR STICK, NOT TOLD
BUT ANY A/T BOX SHIFT FROM PARK TO DRIVE.
IF RPM FALLS HOT ENGIE, THE IAC OR TBW IS FAILING.
YOUR SHOP EVER HEARD OF A SCAN TOOL TO SEE IF TWB IS FAILING? OR IF IAC FAILS.
MISFIRING,.
LEAN BURN ERRORS p017X ?
OR VAST OTHER ERRORS I GUESS HE FEARS FACTS NOT SCANNING, ANY MODERN CAR FIRST.

SOME CARS THIS YEAR, 2006 PETROL (GAS)
LACKING VVT MAY HAVE EGR VALVE LEAKING AND THIS MAKES TBW GO NUTS.
WE HAVE NO SUCH CAR OR 1.4 HERE, SO NO BOOKS ON IT FOR ME TO KNOW WHAT THAT ENGINE HAS FOR EGR, TB OR TBW OR IAC.
AND I CAN NAME 50 CAUSES. BUT WILL NOT NOW.
BAD SPARK PLUGS? 17 YEARS OLD?
IF IT HAS COIL PACKS ? AND NOT COPS
THEN THE HV COIL PACK WIRE SETS ARE NO GOOD THIS OLD

TWB MEANS THROTTLE BY WIRE SEE HUGE MOTOR ON SIDE OF TB (THROTTLE BODY) THAT IS TWB CLEAR AS AS DAY.
MISFIRE, SPARK? BAD?
VACUUM LEAKS,
INJECTORS LEAK OR 1/2 CLOGGED.
LOW FUEL PRESSURE TO RAIL.
IT RUNS FINE SO FUEL PRESSURE IS OK

SCAN THE PCM AND SEE WHAT'S UP./?
EOBD IN EUROPE NEAR LIKE OURS USA OBD2L.
SCAN IT. NEVER SKIP THE SCAN OR WASTE CASHE ON LABOR AND PARTS NOT NEEDED.
GOOD LUCK

Seems like your are describing a outboard motor. If so, the Boat section of Fixya may have more experts that you need. You would want to avoid turning any screws on the carburetor body. The externals on the linkage have some adjustments like throttle stops.

The linkage on boat shift mechanisms are tempermental. They usually combine 2 functions on 1 control lever. They are synchronized that when the transmission shifts from neutral to forward and neutral to reverse the idle speed is low. This keeps the gears from grinding and takes the shock out of the shifting process.

Another thing different than on a car engine is the effect of the propeller on engine rpm. You can change the "in gear"
rpm for both directions by changing prop size and/or pitch.
This also means you can over-rev the engine by having the wrong prop on the boat. There are engine rpm "stops" for the high end too, but some just rely on using the correct prop. As what you may be experiencing with a "stall" can be brought on by

A word of caution. The inboard/outboard engines can have the same problem as outboard engines. The shift levers are synchronized with a pivot system and adjusting the throttle can interfere with the shifting.

You may be able to view youtube videos by searching for these topics.

P0122 throttle/pedal position sensor/switch A circuit low input
P0223 throttle/pedal position sensor/switch B circuit high input
P2101 throttle actuator ctrl motor circuit rang/perf
P2104 throttle actuator ctrl sys-forced idle
P2110 throttle actuator ctrl sys-forced limited rpm

Here is the meaning of the codes hope this helps

Check the wiring to the throttle body, check the supply voltages as well. Check fuses too, it sounds like it received a voltage spike and then lost voltage and is now forcing limited rpm.

Check out related help links to troubleshoot these problem:----Click the link below:---Idles Fine but RPM jumps in drive mode? http://technoanswers.blogspot.in/2012/07/idles-fine-but-rpm-jumps-in-drive-mode.html
---------Mitsubishi Lancer rpm needle bounces? http://technoanswers.blogspot.in/2012/02/mitsubishi-lancer-rpm-needle-bounces.html
--------How to adjust rpm on 2009 dodge charger SRT8?

http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
---------
Engine cuts out at 3000 RPM? http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html

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Cold start problem and vehicle shudder around 2500 to 3500 rpms
http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

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High rpm in neutral? Inconsistant high RPM in neutral? http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html

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Jetski Sputters and Low RPM? http://whatisbyme.blogspot.in/2012/07/jetski-sputters-and-low-rpm.html

--------
Fuel Injection Problem And RPM suddenly increases http://whatisbyme.blogspot.in/2012/07/fuel-injection-problem-and-rpm-suddenly.html

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2005 Toyota Highlander: Engine runs hard RPM below 3000? http://whatisbyme.blogspot.in/2012/05/2005-toyota-highlander-engine-runs-hard.html

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1987 Toyota Camry: RPM Drops going Up hills? http://whatisbyme.blogspot.in/2012/05/1987-toyota-camry-rpm-drops-going-up.html

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Cruise Control stops working, Excessive cranks to start the engine and RPM goes max 2500 http://whoisbyme.blogspot.in/2012/07/cruise-control-stops-workingexcessive.html

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1990 Toyota 4Runner: Engine cuts off when reaches 2000 RPM?

http://whatisbyme.blogspot.in/2012/05/1990-toyota-4runner-engine-cuts-off.html

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1999 Toyota Camry: Erratic stalling and high engine RPM at idle?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-camry-erratic-stalling-and.html

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1995 Toyota LS: Misfire at idle or low RPM http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

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Lexus RX: Tapping noise under Valve Cover At Low RPM? http://technoanswers.blogspot.in/2012/04/lexus-rx-tapping-noise-under-valve.html

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These will help.
Thanks.

sounds like its breaking down, check your ignition system, test your leads, check your plugs, check your ignition coils etc etc etc.

Have you tried cleaning the throttle plates and idle air control motor

check automatic idle speed motor if equipped.

The throttle body needs cleaning. It has some carbon build up, and when the battery went dead the computer lost its learned values, one of which is base throttle position. Now its reset back to factory specs, not accounting for a dirty throttle body. Seen it a million times

Have you tried cleaning out the throttle body and injectors with a cleaner?