Espos4
Well-Known Member
i feel your frustration, i have twins also v drives, one engine will run 4600-4800, the other wont get over 4000. diacom software clearly shows my timing is being retarded TO 24 DEGREES. but i cant find the cause, im not getting any alarms, fuel economy is bad. been struggling with this for more than a year, swapping parts, compression tests, swapping fuel systems, caps rotors plugs wires, ECM's blah blah blah. starting to think vibrations in the tranny are affecting my knock sensor thus pulling the timing down. although the knock sensor will save me from engine damage, it is a troubleshooting hurdle hard to get past. if only there was a way to bypass the knock sensor to see if my rpms will pick back up, then at least i have a clue. but no misfire, cough, sputter nothing. im thinking about putting a rubber oring under the KS to make it not so sensitive. in the two diagrams, you can see the healthy engine's spark advance is hunting and the week engine is flat lined at 24 degrees. i have to manipulate my throttles to make my sync gauge center up. i guess i will continue to peck at it here and there. it really only bothers me when i have a loaded boat and struggle to get on plane, the stronger engine is doing most of the work.View attachment 90506 View attachment 90507
360/24=15.
Are there 15 teeth on the distributor drive gear?
Could the distributor be off by one tooth?