2000 150 john 60* shuts down on take off.

[James R]

Comps all good. Idles great and revs in the barrel. Idles on load but shuts down on take off. Sparks good with new coil bank and power pack.
I believe this smacks of a fuel shortage problem. Checked the fuel filter at the assembly,all clean. Fuel gushes out when prime bulb squeezed. New prime bulb OEM. Pump drawing fuel from a jug at ground level. Fuel in all carb bowls. Stripped carbs and they were clean to look at. Floats set correctly. Cleaned a rebuilt carbs. Fuel gushes out from all the ports in the manifolds when bulb squeezed.
At this point I no longer suspect the carbs.
Would there be a problem with the vapor separator that could cause the problem or is it the fuel pump after all. I don't know how the vapor separator works. Please enlighten me. Any help would be appreciated.

 

[Chris1956]

The Vapor separator is a sealed bowl like a carb bowl. It had an inlet needle, seat and float. It allows the vapor (if any) to be removed from the fuel supply and burned by the motor. The OMS pump and vapor pump create enough vacuum in the vacuum separator to keep the vapor separator filled with gasoline. Fuel is gravity fed to the OMS pump.

if your motor still dies upon acceleration, while pumping the primer bulb, I doubt it is the carbs or fuel system. I would look for a bare wire to the powerpack that shorts when the throttle is opened.

Is she running on all 6 cylinders. Those motors have a shift assist switch that kills spark to 1/2 the motor.


You might disconnect the cylinder head temp sensors to remove that issue. if the motor thinks it is overheating, it kills some spark as well.

 

[James R]

Thanks Chris1956. I know that I am getting old when I miss things like this.
There are no high speed jets in the bowls!! The owner told me that he had changed the bowls. He also told me, when I asked him, that it had never run after the change. Duh. Of course he has thrown away the old bowls complete with jets. I see that they are no longer available from B.N. Do you know of another source apart from Ebay, where I can see only 5. Will need another one.
Part #032758 69D.

 

[James R]

Sorry the part # is 0327558.

 

[Chris1956]

crowleymarine says those jets are backordered. $17 ea Not a bad sign.

Dougrussell says they have all of the various high speed jets in stock. $23-$25 each.

 

[James R]

Thanks for all your help Chris.
Much appreciated.