77' Johnson 6 HP. No spark below 1/2 throttle

[Wee Hooker]

I reciently obtained a well used but deciently salvagable 77' Johnson 6 hp two stroke. It runs strong at top end, has equal (75#) compression in both cyls but has two known problems that keep it from being usefull: 1) The water pump quit after I ran it for only a few minutes. I know what has to be done here. I just dread trying to get a 30 yr old motor apart to get that impeller in. 2)The motor must be started with the throttle 2/3 into the running range as there is NO spark below 1/2 throttle . Basicly spark starts to show on my timing light when the idler wheel on the spring loaded arm ( from carb) hits the last part of the cammed protrusion on the piece under the flywheel ( that I believe) governs spark advance. Any lower throttle setting shows no spark at all and will not allow the motor to even fart. What are likely causes? I'm guessing Points? Shorted wire? Any help or test hints appreciated. Thanks in advance

[Goodoleboy]

Welcome to the forum!I was wonderin how thu hell you ever got it up to half throttle with no spark.You shore muss be one fast rope puller...grin!I spect you have spark at idle also. What you dont have is gas at idel speed.Take that carb off and beat hell out ov it with uh claw hammer to shake all the crud lose inside...then take uh garden hose and wash it out rail good.Whoa...whoa..wait...wait...un minute!My key board just went wacko...!..theirs uh much better way to clean your carb.Clean real good with engine tuner and blow all passages clear with compressed air.PS..dont judge this forum by me...Iam the local comedian....some days!.....other days Iam the local grouch!...grinTwix all of us we can fix your little motor.Good luck!

[Wee Hooker]

Thanks GOB, I've cleaned a carb or two in my years. Some of them even worked again! Still, I'm running a old in line ( not induction ) timing light between the wires and plugs. Neither cylinder see's spark until I open up the throttle ( which also moves the spark advance linkage, etc). This hints that it's something electrical ( or mechanical causing a electrical failure.)No?