Johnson J200 STLCD 1987 will not run at full throttle

[mako 2]

Idle speed no problem but at full throttle it dies out makeing it imposible to get up on plane. What to do?

 

[clanton]

Re: Johnson J200 STLCD 1987 will not run at full throttle

Model number indicates a 1986 GT200 with 35 amp charging system. If pumping the primer bulb why trying to get on plane does not help. I would check the compression,at least 100lbs all 6 cylinders, check spark at cranking rpm with sparkplugs in, spark should jump 7/16 gap.