1989 70HP YAMAHA LOSES MIDDLE CLYINDER

TIRERON

Recruit
Joined
Mar 31, 2015
Messages
1
89 YAMAHA 70-ETLF 3-CLY, cranks & runs perfectly at all rpm's idles smoothly until motor gets hot, middle cly drops or quits running after getting hot 5~8 minutes maybe sooner in warmer weather. carb cleaned & sync air screws correct.......new fuel filter, new fuel pump, all 3 coils new, new spark plugs & caps.
let the motor coll off and its good to go until getting hot again.
anybody had any experience on CDI Box or Stator assembly or is there something else I am missing
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,880
testing voltages while problem shows up like the service manual calls out for CDI inputs and out puts should tell if there is a problem with ignition system
 
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