poor idle/miss

[2cycle]

I have a 74 Inline 150. My symptoms are a rough idle and WOT power loss (occasional). I am currently rebuilding carburetors and replacing pump diaphragm and check valves. My question is regarding the the long black tube that runs from the top of the motor to the bottom cylinder below the fuel pump on the driver's side of the engine. I was told that this is for oil circulation. Upon inspection, I saw that it was cracked at the top where it connects, thus creating a leak. Would this crack possibly affect crankcase pressure to any degree that it could adversely affect idle, fuel delivery or WOT fuel pump vacuum--or any of the above? Thanks for the responses and willingness to help.

 

[dilligafda]

Re: poor idle/miss

Originally posted by 2cycle:<br />I have a 74 Inline 150. My symptoms are a rough idle and WOT power loss (occasional). I am currently rebuilding carburetors and replacing pump diaphragm and check valves. My question is regarding the the long black tube that runs from the top of the motor to the bottom cylinder below the fuel pump on the driver's side of the engine. I was told that this is for oil circulation. Upon inspection, I saw that it was cracked at the top where it connects, thus creating a leak. Would this crack possibly affect crankcase pressure to any degree that it could adversely affect idle, fuel delivery or WOT fuel pump vacuum--or any of the above? Thanks for the responses and willingness to help.

Actually it is for fuel/oil recirculation and yes a crack in that hose will create an air leak and running problem. It also causes a lean condition and can (and will) burn up a cylinder. Get it replaced alnog with the carb/fuel pump rebuild should take care of your running problems.<br /><br />Good luck!