'75 Johnson 15 cutting out @ lower rpm's

[chilifriedpork]

The motor reads 120psi on both cylinders. Motor is on a 12ft aluminum boat.<br /> <br />The problem is at lower rpm's (well before plaining speeds) the motor cut's out for a second, and re-covers itself. Then it does it again, until pushed to higher rpm. The problem doesn't always occur, it seems to be more so when cold(?)<br /><br />The low speed mixture screw only effects trolling speed rpm's. The problem persists past trolling speed.<br /><br />My guess is either the driver coil is acting up, or the blue high voltage coil that goes to the spark plug is acting up. (one of these coils had been replaced, due to poor ideling recently) The other old coil has a slight crack in it, and possibly may be deffective.<br /><br />Any thoughts?