motor stalls when given throttle

Jamescenterconsole

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Mar 31, 2013
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I have a 1982 80hp merc. serial#6175133. I have cleaned the carbs rebuilt the fuel pump and water pump. Compression is within ten percent. I have replaced the fuel, filter and lines to the motor. The motor idels at around 1100 and goes into gear great accepts throttle on the muffs. Put it in the water and it idels great around 1100 and goes into gear great. When I give it throttle slowly it stalls when I give it more quickly it stalls also. It stalls around 2000 rpms either way. If I leave it in nurtral it accepts throttle perfectly on muffs or on the water. From what Ive read on here it seems I may need to readjust the carbs? Any help/ideas would be great. Thanks
 

schematic

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Jan 12, 2008
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1,102
Re: motor stalls when given throttle

Be sure you have all cylinders contributing.
Be sure you get acceptable Max RPM at WOT.
Link and synch as per manual....then...

Lower your idle speed till you have 650 - 750 in gear. Adjust mixture screws for best idle quality.....then back out each idle screw 1/8 turn at a time until hesitation disappears.
 

Jamescenterconsole

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Re: motor stalls when given throttle

Ok I pulled the plugs on direction from here and a good friend . No sign of fire on #3 and #4 the plugs were clean. I will check for spark next and swap coils. I just didnt think it would run that well on two cylinders? Ill keep you posted on what I find. This is what you get when you assume before you post! Thanks for the help. I may need some more!
 

Jamescenterconsole

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Re: motor stalls when given throttle

I switched coils and still no fire. I have cotinunity on the wires from the coils to the ?switch? box. What do I test now and how? Thanks
 
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Jamescenterconsole

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Re: motor stalls when given throttle

Heres what Ive done so far. (Thanks Dave for the info) The number one cylinder has fire 2 looked like it had some by looking at the plugs. I ran the #1 coil terminals to cylinders 2, 3, and 4 and the spark followed down the coil packs. So all of the coils are good. According to page 83 of the CDI guide I swaped the stator leads end to end on the switch box. The spark stayed on the #1 cylinder. CDI says the box is likly bad. However I have not been able to check the trigger yet, still trying to get the parts to make a DVA. Could the trigger still be the problem? I forgot to mention its a thunder bolt ignition dont know if that makes a differance.
 

Jamescenterconsole

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Re: motor stalls when given throttle

Here is my test so far not sure if I did them right.

Digital meter Trigger test
Purp-Wht= 780 w/meter set at 2000ohm
Bro-Wht/Blk= 1270 w/ meter set at 2000k ohm
analog
Purp-Wht=2ohm
Bro-Wht/Blk=0ohm
Digital meter Stator test
Blu-Blu/Wht=60 w/meter set at 2000k ohm
Red-Red/Wht=63 w/ meter set at 2000 ohm
Analog
Blu-Blu/Wht=15 ohm
Red-Red/Wht= 1 ohm
 
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Jamescenterconsole

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Mar 31, 2013
Messages
40
Re: motor stalls when given throttle

DVA Stator test= low out of range and low but in range
DVA Trigger test= low on both
Switch box= bad --switched end to end problem stayed the same-per CDI check
Rectifier=good
I will check the magnets when I get the fly wheel off. Then I plan on replaceing all the above. unless someone has another idea??????????????
 
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