acceleration flat spot " help"

[clay carlson]

Have a 1972 v4 johnson 115,runs grate but, has a flat spot during accelleration
between 2100,2500 RPM. tryed lots of different things that didnt work. am open
to help you could give.

[wholesalemarine]

Clay,
While it's difficult at best to diagnois a performance problem over a forum, most flat spots I have come across have been caused by weak links in the ignition system, whether it's the plugs carboned up or worn spark plug wires etc...
Thanks,
Wholesale Marine

[marty3376]

The issue can also be timing, the spark needs to advance before throttle is given, the boat is probable ok at low RPM or Wide Oen Throttle (WOT). You just need to check the manual to have that timing set to advance before throttle up. my evinrude 70 and 30 was the same way. at a fast idle or troll, you would get a flatt spot or "sputter" at only 1 point in the throttle....any point before or after was ok....mine was timing. youcan adjust the rod that comes off your throttle plate for this. but again check the manual for the spec.