Hello guys. 23 hp briggs V twin on long tail go devil. Crank it up and drop it in water and it runs fine for a very short time then drops to one cylinder. Seem like it does this only under a load. Ran great out of the water. Ran it at 3/4 throttle for 10-15 minutes with no issues. New plugs. No ethanol. Carb is spotless. Haven't dug into it any more at this time. Any ideas??? Thanks

Have you looked at the new plugs? Might be burnt up already. It's gotta be a spark or compression issue

tried three different sets. changed tank and fuel line . changed fuel pump. could it be a bad voltage regulator or a bad coil?

Test the spark, test the regulator and test the compression. Sounds like a spark issue

i saw a post about a diode in one of the coil wires???

I have no idea,

I will do some checking tomorrow. Just hate to replace parts that might not be bad. Had it out this morning. Cranked up fine. dropped it in the water and it ran wide open with no issues then about 30 seconds later dropped to one cylinder.

No need to replace anything yet get a volt meter and a compression tester and figure it out

ok thanks for the help

leak down test also. Doesn't sound like it's diodes. When they go out, it'll run on one cylinder all the time, but as soon as you put it under a load it'll crap out on you. Running for 30 seconds will get it warm enough to trip a bad oil sensor. Check the oil level to make sure it's good, then disconnect the oil sensor & run it to see if the problem is still there. Could just be a bad sensor, or possible bad oil pick up inside block.