1969 6hp fisherman

jonsilva

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Jul 12, 2016
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18
I have a 1969 evinrude 6hp fisherman. It starts and runs really well in neutral. I put the motor on my 11' flat bottom boat and when i put it in gear it does not want to rev up. it only goes just a little past idle even when i turn the throttle to full speed. i can tell that it wants to rev higher because it does for a split second and then drops back down. when i leave it a full throttle you can feel the motor trying to rev up but it never does. any ideas on what this could be?
 

racerone

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Dec 28, 2013
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36,033
Step # 1 is to check spark intensity.-----Does spark jump a gap of 1/4" or more.------Classic symptoms of running on one cylinder.-----When I pick up one of these motors it usually has new coils already.
 

racerone

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Dec 28, 2013
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36,033
Well, ---A motor like that will rev up " nice and high " running on one cylinder.--Your test means nothing here !
 

racerone

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Dec 28, 2013
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Often folks do not want to do testing.---I could show you some coils all cracked and with a hole burned through the bottom.-----So does spark jump a gap of 1/4" or more , yes or no ???
 

racerone

Supreme Mariner
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Dec 28, 2013
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36,033
Pull one wire off and see if it will start.---Repeat with the other wire.----With motor running remove wires one at a time and see what happens..
 

jonsilva

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Jul 12, 2016
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18
ok will do this and see what happens, what should i do if it turns out one cylinder is dead?
 

racerone

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Dec 28, 2013
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Pull the flywheel with the correct puller and inspect coils.---You may find 2 cracked coils or 2 new ones already.---See this all the time.
 

jonsilva

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Joined
Jul 12, 2016
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18
checked the spark and the bottom cylinder has no spark at all, the top cylinder has plenty of spark, do i have to mark the position of the flywheel before taking it off ?
 

F_R

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Jul 7, 2006
Messages
28,195
No you do not have to mark anything. But you do need the correct tools and do the job properly, or you can ruin your motor. You need a flywheel puller (a harmonic balancer puller will do) to get it off. DO NOT use a puller that grabs the outside diameter of the flywheel. When reinstalling, the flywheel and shaft tapers must be clean and dry, and you must use a torque wrench to tighten the nut to 40-45 foot pounds. You also need some sort of a tool to hold the flywheel when torquing on it (strap wrench). There are several You tube videos on the job. A guy named cajuncook2 has some good ones.
 
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