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Fish boy
08-22-2004, 07:02 PM
A friend has a donzi deck boat that we took out this weekend. It has a 350/260hp mercruiser. Starts fine and runs fine for abou tthe first 209 minutes. When it warms up, it will no longer run if given gas or at speeds over 3mph. will idle and cruise at extrmely low rpms, but thats it once it warms up. Once it cools off, it is fine again.

Since I am used to breaking outborads, I thought I would asks the professionals before I attempt to really screw this one up. ;) Any thoughts?

fish

gcarter
08-22-2004, 08:06 PM
Hi Fish!
The tank vent may have a mud dauber in it.
If it happens again, crack open the fill, it'll probably run.
After that;
fuel filter
anti-syphon valve
:smile:

mattyboy
08-23-2004, 09:10 AM
I was thinking more in the way of a hole in the pick tube of the tank, fine when full but when the fuel level drops and the hole gets exposed.... could be crap getting sucked up to??

Walt. H.
08-23-2004, 10:54 AM
Vent line glog as mentioned above will do that causing a vacuum condition in your fuel tank and will re-normalize after that cool down period. Or a tired fuel pump diapham, if it isn't that another thing to look at is to try this:

Swap out the ignition coil for another one just to make sure its not that, that is breaking down. If its old like ten years or more they usually start to stop doing their hot spark stuff after they warm up to operating temp and your engine can spudder/ surge and not run above idle speed. But that usually happens after 15-20 minutes of running time.


Walt

Fish boy
08-24-2004, 06:58 PM
thanks for the suggestions guys- definitely did not think of any of the things suggested. I will let you know how it works out.

Thanks,

fish