1996 102 hp force no mid thottle

96trophy2002

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Oct 5, 2011
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1996 102 hp force My motor will start out fine but if I let it run at 2200 rpm when I go to full thottel it will struggle to get to 3300 rpm then it seem to cough and pick up. It runs great at 4100 to 5200rpms also my voltage is now 15 to 16 volts and sometimes goes back to 13 14 volts when it is 15 no tach read out

Thanks for all the help in advance
Shawn
 

bentle

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Aug 2, 2011
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492
Re: 1996 102 hp force no mid thottle

Did you mean you have a 96 120 hp??
At the start of the forum page there is a sticky which has a link and sink by FrankA, do that to start with.
Do compression and spark test as well.
You may have one or more fouled plugs causing your cylinder or cylinders to hit and miss.
As far as the voltage your running I would suspect loose or broken wires or a bad rectifier shorting out.
What repairs have you done so far and checked out?
 

96trophy2002

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Re: 1996 102 hp force no mid thottle

I did a compression check at start of season, 3 weeks ago was great(150 psi) and = in all cyls I am going to hook up a fuel tank with known good gas, check for spark and syn carbs as per sticky, test fuel pressure, inspect plug, look for wiring problem, I may rebuild both carbs and fuel pump just because it only cost about $30 I hope I can put to use all the great information I found on this forum Thanks for all the help guys Shawn
 

pnwboat

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Re: 1996 102 hp force no mid thottle

Sounds like you may have a rectifier/regulator problem. Output should never go above 14.5 volts on your motor and should stay at that level once you get up past 1500 or so RPM. If the rectifier portion is bad, it will also affect ignition spark. The tach signal comes off of the gray wire ( I think it's gray) on the rectifier/regulator assy.
 

96trophy2002

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Oct 5, 2011
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Re: 1996 102 hp force no mid thottle

Went to boat yesterday installed new filter/septerator, Synchronizing Carbs. When I tried to adjust idle screws on bottom carb no change in rpm, when I did top I was able to stall motor. I had also run it off a new tank of gas 6 gollons/1 +qt oil
I just got the carb rebuild kits and a rebuild kit for fuel pump today. the regulator is being shipped from a differant location. At full thottle it runs great, but when I go to 2200 rpms for a minute then try to throttle up it will bog and then it works it way back to full thottle. Any help would be great since the boat is a hour away. I removed carbs and brought them home. Will rebuild them this week and go back install them, fuel pump kit, and the voltage regulator if i have it. Any other ideas?

Thanks,
You guys are a great help Shawn
 

bentle

Chief Petty Officer
Joined
Aug 2, 2011
Messages
492
Re: 1996 102 hp force no mid thottle

Does the bottom carb have any fuel in the bowl?? How does primmer bulb look?
May not hurt to check fuel vent for any plugging. Also remove fuel pick up tube in the tank
and check for plugging at the pre screen and make sure its not sucking any air.
how are the fuel lines? With age they can crack and allow air in the fuel lines, and can also
collapse thus pinching off fuel supply. Thank the ethanol.
After you get the carbs rebuilt and pump post what you get after reinstalling.
Careful not to over tighten air/idle mix screw or you may damage the needles and seats.
 

96trophy2002

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Oct 5, 2011
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Re: 1996 102 hp force no mid thottle

I ran it off a 6 gollon external tank with new fuel line and bulb to take the gas tank and hoses out of the equation
When I get the others changed out I will post results
Thanks
Shawn
 

96trophy2002

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Oct 5, 2011
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Re: 1996 102 hp force no mid thottle

Update:
Problem 1 Rebuit and reinstall carbs,Synchronizing Carbs,replaced all fuel lines,and filled with fresh fuel. Was unable to take out in bay due to 4 to 7 foot seas and 20 to 30 knot winds. Not willing to risk a break down in those conditions, But when I set the idle at 850 it ran smooth as could be. @ 2200RPM SMOOTH
@ 3000RPM SMOOTH
@ 4000PMS SMOOTH no hunting up and down
Installed a fuel pressure guage and got 4 Psi, When I looked at the manual it said nothing about pressure. It said to check vacuum on inlet side of fuel pump
DOES ANYONE KNOW WHAT THE PRESSURE SHOLD BE ?
Problem 2
Istalled the new regulator and tested voltage 13 @ Idle 14.2 @3300 rpm and the tach is working great
 

96trophy2002

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Oct 5, 2011
Messages
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Re: 1996 102 hp force no mid thottle

Update:

Replaced head gasket and tested STILL HAVE SAME PROBLEM When I go from 2300 rpm to full throttle it just cough and sputters when it gats going goes to 5200 rpm and runs fine When I come off the rpms It has same problem to get back to 5200 When I checked plugs no white milky stuff on them a little dark but not bad Could this have something to do with spark going to plugs? PLEASE HELP I AM LOSING MY MIND AND THIS IS NOT HELPING
 

pnwboat

Rear Admiral
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Oct 8, 2007
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4,251
Re: 1996 102 hp force no mid thottle

Well at least you have one problem solved.

How far out do you have the idle mixture screws turned from lightly seated?
 

96trophy2002

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Oct 5, 2011
Messages
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Re: 1996 102 hp force no mid thottle

Does anyone know the gap seting for a spark test on a 1996 120 force? and how a

Part Number: 511-9775
Name: PACKLOAD RESISTOR
Replaces: 511-9775 PL88
is use to check coils
 

96trophy2002

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Joined
Oct 5, 2011
Messages
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Re: 1996 102 hp force no mid thottle

Replaced head gasket and I am still getting water on the bottom 2 spark plugs Where else can water come from? Any ideas what to do next? I also had white fluid coming out the bottom carb when I tilted the engine up Thanks Shawn
 
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