I am currently running on one cylinder on a vanguard 36. Occasionally the engine will run on both cylinders. I have run through the gambit of troubleshooting to include

1- set and confirmed valves adjusted properly

2- getting spark at both plugs. When I pull the plug wire on cylinder the engine is running on, and leave the non running cylinder plugged in to the spark plug that cylinder will run.

3- no intake or exhaust leaks

4- fuel clean and new fuel filter

5- carb cleaned

Not sure where else to go with it. Any suggestions?

Leakdown test. Wrap the plug boots all the way back to the cowling, or even the coil, with electrical tape in case you're leaking spark.

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Now, on the trailer, typically cylinder 2 won't do much. Only under load does it start to work. My engine doesnt sound much, if any, different with cylinder 2 spark plug boot unhooked. Different story in the water in gear.

#CFFITR
#GhostBoat
#Whoneedsphysicsihaveamudmotor

Nope. Never put a gun on it.

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#GhostBoat
#Whoneedsphysicsihaveamudmotor

I just had the same problem. After much trial and error, I found that one of my spark plugs had a hairline crack in it. New plugs fixed it. Now I've also had a diode go bad, which will cause it to run on one cylinder.

I’m battling a similar issue myself. I’ve been through the mikuni (thoroughly), checked and rechecked last (Willy fast YouTube method), when I get home From thanksgiving now I’ll pull my coweling and run electrical tape. If that doesn’t do it I will be at a a complete loss. My next move will be to lap my valves or have a valve job done.