Quote:
Reccommended rpm range for that I-6 115 hp merc is 4750-5250 what pitch prop are you running?
|
My 1989 Mercury book says that '83-'88 Mercury/Mariner inline 6 115hp motors with AGI (non-distributer) ignition should run 4800 - 5500, the inline 6 90hp should run 4750 - 5250, and the inline 140 should run 5000 - 5800 rpms. It also suggests 4800 - 5400 for all Thunderbolt ignition inline 6 models from '77 - '83. I have owned and run more than a dozen inline 6 motors on recreational boats, and I set them all up to run 5700-5800 max rpms.
I used to race an inline 6 XS1500 150 and we turned 8000 rpms, and I've seen more than one turning close to 9K. But you absolutely do not want to run between 6200 and 6700 rpms as the harmonics will cause your motor to auto-destruct.
FTR, I heartily recommend either running 92 octane gas, or retarding the timing to 21 degree max advance.
__________________
Common Sense is learning from your mistakes. Wisdom is learning from the other guy's mistakes.
Fr. Frank says:
Jesus liked fishing, too. He even walked on water to get to the boat!
Currently without a SeaCraft 
(2) Pompano 12' fishing kayaks
'73 Cobia 18' prototype "Casting Skiff", 70hp Mercury