I got a 1989 120 Johnson and need to know the rpm range on it. Took it out today with a 16'8" champ and 22p prop and 3.5 below pad and only got 4800 rpms at WOT ?
I got a 1989 120 Johnson and need to know the rpm range on it. Took it out today with a 16'8" champ and 22p prop and 3.5 below pad and only got 4800 rpms at WOT ?
not too sure what 3.5 below pad means exactly, but 4,800 RPM is nowhere near enough.
Todd Savage
'93 Javelin 363 FS
'82 115 Johnson
OK I did a compression check and the readings are good I guess. tr 110, br 110, tl 115, bl 120. I can't figure out why its not running the rpms it should? Please help. Could it be no fire? All the plugs looked good and pretty even on the color.
Need to make sure your throttle plates are opening fully when you give it wide open throttle. Take the cover off the carbs and make sure the plates are fully open (90*) when the throttle fully depressed. No need for the motor to be running. Also watch the linkage for the timer base to make sure the timer base is hitting the wide open stop.
OK the port side butterfly's are VERY SLIGHTLY over 90%, but not much. The bar on top goes all the way over at wot. OK NEXT, lol
Starboards need to be at 90* too. Need to check if the stop on the timer base is hitting the wide open stop on top of the motor and have wide open timing checked.
All 4 butterflies are atleast 90%, the port side is a hair over 90%. I'll see if I can get the timing checked. Is that done while running? Sorry if that a stupid question, lol. I'm trying to learn.
Reply With Quote