1996 force 40 WOT missing

Chris35rt

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Aug 3, 2016
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First time poster here. I have 1996 force 40 that when running at WOT has what feels to be a miss or a surge in it an it also does it sometimes at half throttle. Its really hard to explain since there is no real power loss. I have check the compression and both cylinders are 115. Only thing that has been replace was spark plugs last year and fuel pump last month also the carburetor was removed and cleaned. Anybody else ever had this problem? Any ideas what I should look at next?

Thanks,

Chris
 

jerryjerry05

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May 7, 2008
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High speed miss: could be the fuel line connections, the fuel has water, the stator, the trigger, the float level is set wrong, the reeds bad, dirty carb, diaphragm in the primer going bad.
Since it seems to run fair, I'd look at the first 2 and the float level.
 

Chris35rt

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Aug 3, 2016
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Thanks Jerry. I took a sample of the fuel from the tank and didn't see any water in the fuel also based on the manual I set the float level and parallel with the body I'll start with fuel line connections next. But yes overall the motor runs and idle really well for motor that old, plus while I didn't mention it the motor was stored for about 8 years with no fuel and just brought back to life last year.

Chris
 

Chris35rt

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Aug 3, 2016
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Well i'm back, I done everything listed above the only thing i didn't mess with was the trigger and stator, Do you think it might be the coil packs
 

Chris35rt

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Aug 3, 2016
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No i doesn't jerk at all and I just recently had the lower unit rebuilt because of a busted forward gear.
 

pnwboat

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Oct 8, 2007
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Do you have a clear se through fuel filter between the fuel pump and the carburetor? This is helpful in trouble-shooting fuel delivery problems.

Try squeezing the primer bulb at WOT to see if that has any affect.
 

Chris35rt

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Aug 3, 2016
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Do you have a clear se through fuel filter between the fuel pump and the carburetor? This is helpful in trouble-shooting fuel delivery problems.

Try squeezing the primer bulb at WOT to see if that has any affect.

I do have a clear fuel filter. Tried squeezing the primer bulb last time that didn't have any affect. Last time out I put 12 gallons of 92 octane ethanol free verses what i usually run 89 octane and it did seem to run better, could it be that this motor just runs better on the higher octane stuff or is it that ethanol is just that bad?
 

jerryjerry05

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You could have a tiny piece of dirt the size of a pin-head clogging the system.
Check the fuel pump diaphragm.
​You check the reeds?

You might recheck/ remove the inline connectors?
 

pnwboat

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Did you happen to see if the fuel filter was staying at least 3/4 full while running? With no air bubbles?

Check the ignition trigger wires that go to the ignition trigger assy, under the flywheel. The trigger assy moves when you push the throttle handle forwards and backwards. This advances and retards the ignition timing according to engine speed. The wires can rub against the block and wear away the insulation causing ignition problems when the trigger assy/wires are at a certain spot.

Make sure the idle mixture screw on the carburetor is approx. 1 to 1 1/4 turns out from lightly seated.
 

jerryjerry05

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The air screw controls the low speed operation and shouldn't have any effect on the high speed.
 

Chris35rt

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Aug 3, 2016
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Problem solved. It was a bad spark plug. Would have never thought it was that since I replaced them last year and plugs still looked good. New NGK's put in and its rocking and rolling now. Thanks everyone for all the help.

Chris
 
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