please help..New -old boat engine issues-

[surftodd]

1988 merc 5.7 v8- purchased boat a month ago-
my issues are

hard to start when engine has been running- I need to put it into full excelleration in order to get it started then pull back quickly

when left idling she will eventually stall out after 3-5 minutes

stalls some times between shifts- usual at most worst time possible- next to a strangers $100k boat

Cruises at 24 mph at 2600 rpm- should be 35 mph at about 3400 rpm
wot 27 mph at 3000 rpm- should be close to 40 mph at about 4500rpm


replaced plugs/wires and cap....

anyone know my next step? I am think the timing.. Thanks in advance for any help

 

[64osby]

Re: please help..New -old boat engine issues-

My first thought is it's not running on all cylinders.

Second thought is fuel tank vent not open, causing vacuum.

Third would be fuel filters old and or carb gummed up.

A timing check would also be good but it seems that your engine is starving, not getteing enough fuel, if it is running on all cylinders.

Good luck.