Force 120hp - Idles but won't accelerate

J

jburdadams

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greetings! you all helped me back in June, so I'm back with another education opportunity. Last time, it would run wide open but wouldn't idle. Different problem this time, that seems related to 'flooding' :
the old 1999 120 Force will idle slowly indefinitely, but will choke down once you advance the throttle or try and put it in gear. Ran fine last weekend, and is full of new gas. Did all the suggestions you all provided back in June: new plugs, checked and tightened all hose clamps, fuel pump, in line filter, float bowl gaskets, idle mixture screws are adjusted per the manual (not touching those again, believe me), adjusted carb linkages, etc, no air leaks. Bulb gets nice and tight, but obviously, too much fuel even though i'm giving it minimal choke. i might add that the excess fuel looks milky blue-white, which is a new one on me.

thanks in advance for your help!
 
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pnwboat

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Re: Force 120hp - Idles but won't accelerate

Milky looking fuel is usually a sign that there is water contamination. Where exactly are you seeing the "milky fuel".
 
J

jburdadams

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Re: Force 120hp - Idles but won't accelerate

pnwboat said:
Milky looking fuel is usually a sign that there is water contamination. Where exactly are you seeing the "milky fuel".
Click to expand...

excess fuel runs over into the plastic cover in front of the carbs. that's where i see it. thanks
 
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Jiggz

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Re: Force 120hp - Idles but won't accelerate

jburdadams said:
excess fuel runs over into the plastic cover in front of the carbs. that's where i see it. thanks
Click to expand...

If it's there you see it then it is perfectly normal since it could have be contaminated with the water that is already on the bottom cowl. And the only reason there should be fuel flowing out of the carb is if the engine is tilted up more than half-way. So does the engine even stay running when placed in gear and continue to idle even when the control throttle is move forward? Or are you saying it will not accelerate because it dies as soon as you place it in gear? If it is the latter, check make sure you have the idle set properly, i.e. 900~1000 RPM in neutral and around 700~800 in gear idling.
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

Jiggz said:
If it's there you see it then it is perfectly normal since it could have be contaminated with the water that is already on the bottom cowl. And the only reason there should be fuel flowing out of the carb is if the engine is tilted up more than half-way. So does the engine even stay running when placed in gear and continue to idle even when the control throttle is move forward? Or are you saying it will not accelerate because it dies as soon as you place it in gear? If it is the latter, check make sure you have the idle set properly, i.e. 900~1000 RPM in neutral and around 700~800 in gear idling.
Click to expand...

It will idle but shuts off immediately if you advance the throttle any amount, or put it in gear. Thanks
 
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Jiggz

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Re: Force 120hp - Idles but won't accelerate

Do you have a tach? What is the idle rpm setting in neutral? in gear idle?
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

Jiggz said:
Do you have a tach? What is the idle rpm setting in neutral? in gear idle?
Click to expand...

There's the usual tach in dashboard. Registers what appears to be around 800 rpm in neutral, which is a little slower than it used to idle when it was running correctly (around 900 rpms). I purposely set the idle a little higher last time i adjusted the carbs. Not sure what it runs in gear since it shuts off.
 
procraftguy

procraftguy

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Re: Force 120hp - Idles but won't accelerate

Try squeezing ball it may be fuel pump also compression low compression +load will kill it also 800does is pretty low back out the idel screw 1/8 turn hope that is some ideas that help
 
further

further

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Re: Force 120hp - Idles but won't accelerate

Should be 1000-1100 in neutral, around 750-800 in forward gear
 
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Jiggz

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Re: Force 120hp - Idles but won't accelerate

jburdadams said:
There's the usual tach in dashboard. Registers what appears to be around 800 rpm in neutral, which is a little slower than it used to idle when it was running correctly (around 900 rpms). I purposely set the idle a little higher last time i adjusted the carbs. Not sure what it runs in gear since it shuts off.
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800 RPM in neutral is little low. Adjust the idle screw (NOT LOCATED ON CARBS BUT BOTTOM OF TIMING TOWER) to achieve 1000 RPM in neutral on muffs. If it still dies when placed in gear, it's time to do a compression test on all cylinders.
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

thank you one and all. I will try your suggestions over the next few days (weather permitting!) and report back. thanks for your quick responses.
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

jburdadams said:
thank you one and all. I will try your suggestions over the next few days (weather permitting!) and report back. thanks for your quick responses.
Click to expand...

considering replacing/rebuilding the fuel pump at this point. Crowley Marine shows a 'kit' for around $90.00. Just want to make sure i'm getting everything i need, or maybe i only need diaphragms and gaskets etc? welcome your suggestions.
 
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Jiggz

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Re: Force 120hp - Idles but won't accelerate

Typically, all you need is just the fuel diaphragm. Are you replacing as a result of testing? or just guessing it is the fuel pump. Since you already have an inline filter (see thru or clear filter between fuel pump and carbs) if that filter doesn't get below 50% in fuel, I do not see a reason the fuel pump to be the source of the problem. Have you raised idle rpm to about 1100 (in neutral) and still dies when engaged? If so, you need to do a compression test first on all cylinders before going any further or spending $$$ unnecessarily.
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

Jiggz said:
Typically, all you need is just the fuel diaphragm. Are you replacing as a result of testing? or just guessing it is the fuel pump. Since you already have an inline filter (see thru or clear filter between fuel pump and carbs) if that filter doesn't get below 50% in fuel, I do not see a reason the fuel pump to be the source of the problem. Have you raised idle rpm to about 1100 (in neutral) and still dies when engaged? If so, you need to do a compression test first on all cylinders before going any further or spending $$$ unnecessarily.
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In line (see thru) filter is mounted before the fuel pump, not between pump and carbs. should I relocate? I'll address this, and the idle first and see if that works, then possibly replace the diaphragm. will be in touch, and thanks for your help.
 
baldtire

baldtire

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Re: Force 120hp - Idles but won't accelerate

How did this work out? I'm having similar issues but I'm not getting enough gas. My in line filter goes dry upon acceleration. Never is even close to 50% full. My bulb won't go hard either.
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

will let everyone know once i work on it this weekend. thanks
 
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jburdadams

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Re: Force 120hp - Idles but won't accelerate

I hate to admit it, but i think this is more of an operator behavior than anything else. I've been advancing throttle slightly (not in gear) while trying to crank it. even with minimal choke, it still apparently seriously floods the engine to the point where the only solution is to let it sit an lonnnnnnnnnnng time. what seems to work is pumping the bulb nice and tight, leaving in neutral, pushing the choke 1 or 2 times, then bumping it repeatedly until it finally starts. this worked fine today, and accelerated and decelerated just like it's supposed to. so all this hoopla could have just been me getting old :) welcome your constructive thoughts - no heckling the old guy please :) thanks!
 
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mandasboat

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Re: Force 120hp - Idles but won't accelerate

jburdadams said:
I hate to admit it, but i think this is more of an operator behavior than anything else. I've been advancing throttle slightly (not in gear) while trying to crank it. even with minimal choke, it still apparently seriously floods the engine to the point where the only solution is to let it sit an lonnnnnnnnnnng time. what seems to work is pumping the bulb nice and tight, leaving in neutral, pushing the choke 1 or 2 times, then bumping it repeatedly until it finally starts. this worked fine today, and accelerated and decelerated just like it's supposed to. so all this hoopla could have just been me getting old :) welcome your constructive thoughts - no heckling the old guy please :) thanks!
Click to expand...

Jiggz did a great write-up for me that has helped my problem. Especially regarding the choke, It's suppose to be held in when you start up the motor, not pushed in a few times. This makes a huge difference.

Jiggz said:
For starting problems, make sure you pump the primer bulb until it is firm. Use the standard starting procedures:
1. Place control lever in fast idle
2. Engage choke by pressing down on ignition switch, turn key to on and start while continuing to press down.
3. Continue cranking until engine sneezes or starts but no more than 10 secs.
4. If engine sneezes but not start running, place key back in off position. Try again but this time do not engage the choke. If you continue to engage the choke you will flood the carbs and making it harder to start.

If engine will neither start or sneeze check for sparks and finally check for compression. Usually, if you have good compression, you can try using a spray bottle with oil-gas mix in it and try starting the engine while spraying into the carbs (you will need to remove the carb covers to do this. If the engine sneezes it means you have fuel problem related if not then it is electrical in nature.
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Keep choking it will flood the carbs and fuel will being spewing out. Hope that helps.

Mike
 
J

jburdadams

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Re: Force 120hp - Idles but won't accelerate

got it. sure appreciate the feedback!
 
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Jiggz

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Re: Force 120hp - Idles but won't accelerate

I still personally recommend relocating the clear fuel filter between the pump and carb intake or just add another one since they cost less than $10 each (I use Walmart's $3.50 3/8" connector paper filter). There is a primary filter in the fuel pump itself and the purpose of the clear filter is more of troubleshooting aid and of course as a secondary filter in case the fuel pump diaphragm itself gives.
 
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