Engine burn lot of gas and will not turn off

[mstaylor77]

Hello,

I have a Mercruiser 5.7L 350 Mag alpha one. I started my boat up this year and had a couple of engine problem that I have been able to correct by reading similar post here on iboat. However, for my current problem I have not been able to find similar problem. This all started with my engine would idle fine in the driveway with muff and once in the water would stall out and would not run under 1500 rpm. After reading a couple of posts online, I replaced the following. Water/fuel separator, fuel filter, spark plugs, and cleaned/rebuild carb. After all this, the engine would start and idle great. My latest problems are; it is burning more gas than before. When I turn the engine off it will keep running. I sometime have to turn it on and off 3-4 times before, it will stop running. I?m not sure on where to start checking for possible issues. Thank in advance for all your help.

Michael

 

[Black as]

Re: Engine burn lot of gas and will not turn off

Sounds like pre-ignition your idle at 1500 rpm is to high

 

[Bondo]

Re: Engine burn lot of gas and will not turn off

My latest problems are; it is burning more gas than before. When I turn the engine off it will keep running.

Ayuh,... Sounds like ya screwed up the carb rebuild... Float set to high is my 1st guess...

 

[boat127]

Re: Engine burn lot of gas and will not turn off

did you set the float with the manual specs or the spec sheet that came in the kit? you could have the float set to high as bondo said or maybe you have the idle mixture screw(s) backed out to far. its best to set your idle to the proper idle per your manual then adjust your throttle cable tension so when you back off the throttle it will return to the proper idle speed but you dont want it set to tight

 

[mstaylor77]

Re: Engine burn lot of gas and will not turn off

I used the manaul spec when setting the float. Should I have used the crab kit setting? I'm planning on taking the crab apart again tmorrow and rechecking the float level. I will then reset my idle. I had to replace my water pump this weekend. Thanks for the support.
Michael