1990 Johnson 60HP VRO - loss of power
I've read hundreds of threads/forums, any help/thoughts on my issue would be appreciated, thanks!
I have a 1990 Johnson 60HP VRO (model no.: j60ELESM). VRO still intact. Entire head was rebuilt professionally two years ago - only put about 20 hours on the motor last year. Motor is on an '84 17' grady white tournament (permanent gas tank) - I always dutifully added gas saver/conditioner each time I added gas to the tank last year. Motor was fogged last winter. New plugs (not the "Q" Champions, the regular ones). Gas line has new RACOR (S3213) fuel filter installed along with new oil res. Water streams out of pee hole and exhaust. Temp sensor out of top of block is tan w/ blue stripe.
THE ISSUE: The motor starts and idles great - can troll forever with it. When the motor is powered up it will run at WOT sometimes for 10min/20min + and then will suddently drop down in rpm and perform like its in "SLOW" mode - however, this drop in rpm is only while in gear - if I put it in neutral it will rev up - so, i'm not sure if the engine is actually going into SLOW mode. After a while (sometimes 5 min sometimes 30min - after shutting down, starting up, the motor will run fine again in gear) No alarms sound - however, I have not noticed any "beep" when putting the key in the ignition, not sure if horn is connected. When I called the marina that rebuilt/sold me the engine - he said it sounded like a 'bad fuel' problem. Any thoughts are appreciated. Thank you.