Hard to start and no idle

S

Sally10

Recruit
Joined
Jun 15, 2022
Messages
3
Hello,

I recently got my 120HP tuned up from a company. took it back 3 times and still not running good. It will not start unless I pump fuel arm to carbs then it starts. it will not idle and sounds rough.
After hours of research and reading I noticed the idle screw was back off. I set screw back to body of motor and reset the shutters on the twin carbs and I got it to start. But it still sounds rough and it shakes while running, like puttering. I played around with idle screws for both carbs starting at 1 full turn out. still the same.
I have it set now but need some fine tuning. Can anyone guide me hear.
I am also looking for repair and maintenance manual for 1993 force 120hp outboard

I have to reset the throttle cables. How do i do this?
 
R

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,516
How did it run for you last season ??----You must start trouble shooting with a compression test.-----Post your numbers.
 
jerryjerry05

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,085
Compression test????
You say you pump the fuel arm and it helps it start.
That would only help if you were turning the key as you pumped. ??
Pushing the key in and out as you turn the key would do the same thing as
these carbs don't have an accelerator pump like the older cars had.
The primer has a diaphragm it too can get destroyed with a backfire, pinch off the hose to the motor after starting to see if that helps with the way it runs?
Did it backfire or cough at all?? if it did then you could have blown a port cover gasket(maybe 2 or 3).
That would cause it to run rough.
The air screws: no amount of adjusting will help if the gaskets are bad.

Once it starts try spraying starting fluid around the intake side of the motor, under the coils/pack and under the carbs. If that makes it run different?? then your sucking air somewhere.
Ebay for the service manual.
Be careful when buying, they sell a parts book and it does nothing for service.
 
R

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,516
When trouble shooting an outboard , a compression test is step #1---always !!
 
S

Sally10

Recruit
Joined
Jun 15, 2022
Messages
3
jerryjerry05 said:
Compression test????
You say you pump the fuel arm and it helps it start.
That would only help if you were turning the key as you pumped. ??
Pushing the key in and out as you turn the key would do the same thing as
these carbs don't have an accelerator pump like the older cars had.
The primer has a diaphragm it too can get destroyed with a backfire, pinch off the hose to the motor after starting to see if that helps with the way it runs?
Did it backfire or cough at all?? if it did then you could have blown a port cover gasket(maybe 2 or 3).
That would cause it to run rough.
The air screws: no amount of adjusting will help if the gaskets are bad.

Once it starts try spraying starting fluid around the intake side of the motor, under the coils/pack and under the carbs. If that makes it run different?? then your sucking air somewhere.
Ebay for the service manual.
Be careful when buying, they sell a parts book and it does nothing for service.
Click to expand...
Could you recommend a manual or link to the right service and repair manual?
 
jerryjerry05

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,085
I'll see if I can locate a manual???
Untill then try U-tube and look for video's
 
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