[mercurylover]

Hi I Have A 1981 140 Evenrude V4 When Started Cold Runs Great For About 5 Min Till It Warms Up Then Seem To Drop Both Bottom Cyl I Rebuilt Carbs New Coils I Had A Spark Tester On While Running Have Spark On All Cyl Comp Good And Even Any Help Would Be Great Thanx

[diver_down]

Originally Posted by mercurylover

Hi I Have A 1981 140 Evenrude V4 When Started Cold Runs Great For About 5 Min Till It Warms Up Then Seem To Drop Both Bottom Cyl I Rebuilt Carbs New Coils I Had A Spark Tester On While Running Have Spark On All Cyl Comp Good And Even Any Help Would Be Great Thanx

get a DVA, check voltage from charging coil on the stator (AC) and the trigger voltage as well (around .5 V i think). check voltage after regulator (if you have one, should be around 13V DC). mine does the same on muffs, the windings on stator seem shot. if stator checks out than most prob it's the power packs.
Mine is a V6 150, 1985 so it might be different, take this with a grain of salt.

[jonesg]

Try a timing light to see if it drops spark when warmed up.
Try shooting fuel in the 2 lower carbs when it bogs down, just to see if it picks up.

[tashasdaddy]

you also could be running out of fuel in one carb. read ethanol. http://forums.iboats.com/showthread.php?t=299680