why did only one cylinder burn up?

[Phillip]

on my 1984 johnson 115 hp equipped with a brand new vro pump, oil holding reservoir, oil line and primer bulb, not to mention me and my dad just got done overhauling this engine. the second time we had it out on the water one cylinder burnt up on us... i would like to know what would cause a single cylinder to burn up because the engine was running great not to mention the water pump was brand new also. could it be a plugged water jacket in one head if so how would i go about unplugging it? ::'(

also i did not install the pulse limiter... would this cause a problem with the vro pump at all?????!!?!?!?!!?

 

[emdsapmgr]

Re: why did only one cylinder burn up?

If you had an oiling problem all would go bad at the same time. Look for a lean condition: Check the carb jets for the bad hole-possible restriction in the jets for that one side. Possible-too much timing also. Could be an overheat: check to see that you have all 4 rubber water deflectors in the block. You did not mention replacing the thermostats-a must on any rebuild. Are the pressure relief valves functional? Did you check to see if the two holes in the valve body were open? What did the spark plug look like, compared to the others?

 

[Phillip]

Re: why did only one cylinder burn up?

If you had an oiling problem all would go bad at the same time. Look for a lean condition: Check the carb jets for the bad hole-possible restriction in the jets for that one side. Possible-too much timing also. Could be an overheat: check to see that you have all 4 rubber water deflectors in the block. You did not mention replacing the thermostats-a must on any rebuild. Are the pressure relief valves functional? Did you check to see if the two holes in the valve body were open? What did the spark plug look like, compared to the others?

The thermostats are brand new. the hoses in the block are all there im not sure if there plugged or not but how would you check to see if the pressure relief valves are functional???