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1977 evinrude 6hp 6704m

N

NOBOAT BROWN

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Can incorrect carburetor float level cause lower cylinder to foul spark plug? Head gasket new, fuel pump rebuilt, new impeller working fine, compression 70 + in both cylinders. Black oil slick in barrel. With clean plugs it starts and runs great but not for long.
 
Does spark jump a gap of 3/8" on both leads?----I have numerous of these great 6 HP motors from 65 to 79.-----I often find the thermostat stuck open on these.----A cold motor will foul plugs.
 
racerone said:
Does spark jump a gap of 3/8" on both leads?----I have numerous of these great 6 HP motors from 65 to 79.-----I often find the thermostat stuck open on these.----A cold motor will foul plugs.
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THERMOSTAT NEW ALSO. ALTHOUGH WATER FROM WEEP HOLE IS NOT HOT. NOT SURE IF IT SHOULD BE,
 
Evinrude 1977 6hp #6704M with CD ignition. Upper cylinder has great spark. Lower has extremely weak to none. What can be the cause other than coil if anything?
 
It could be the CDI unit itself but try swapping coils first to see if the weak spark goes to the top. You could just switch around the input to the coil from the other coil wire input without moving the coil itself. Small jumper wires can help.
 
timguy said:
It could be the CDI unit itself but try swapping coils first to see if the weak spark goes to the top. You could just switch around the input to the coil from the other coil wire input without moving the coil itself. Small jumper wires can help.
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Brain Teaser! On Saturday good spark was on upper cylinder. No spark on lower. On Sunday it was reversed.
 
Well----You may have a broken wire from magneto to the powerpack ( CDI ) .-----But 9 times out of 10 a new powerpack fixes spark issues.
 
Factory or SIERRA;-----If that is not the issue , you have a handy spare for the tackle box.---A 3/8" wrench beside it.
 
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