Reply To: 1953 Big Twin Fires on Two but Runs on One Cylinder Only

[Don]

Like I said, pulling that exhaust cover can be a messy job, I would hate for you to do that based on our guess…So, how about removing the gearcase so the water pump won’t be damaged, then starting the engine to see if it runs on two cylinders with no water going through the powerhead….
And, just to confirm your findings, you could always hook up a water hose to the water tube. Start the engine with no water going through, if it seems to run on two cylinders turn on the water hose, it should drop back down to one cylinder if water intrusion is an issue…