Mercruiser 30 wonbt idle

"I have a 1998 Mercruiser 3.0

"I have a 1998 Mercruiser 3.0 which I am having problems with. I have no problem starting the engine, and it seems to run well at 3000 RPM, but I can't run at lower RPMs, and I can't seem to idle. The engine chokes out when I lower the throttle. It seems the engine is starving out of fuel. I have run the boat for 4 - 5 miles of open water at 3000 RPM, but can't run at no-wake speed or idle.

I have done much work trying to resolve this problem with no success. See list below.

* Completely drained the gas tank in put in 5 gallons of fresh gas with stabilizer.
* Checked vent hose for good ventilation.
* Torn apart the carburator (which was pretty clean) and cleaned it and installed a new gasket kit.
* Replaced the fuel pump.
* Replaced the spark plugs, spark plug wires, ignition coil, distributor cap and rotor.

When the engine is cold, the choke closes and opens within 10 - 15 seconds after staring the engine. Does this seem normal for 80 degree weather? I am now completely out of ideas. Any thoughts or help would be greatly appreciated.

Ron F."

Check the engine timing; since

Check the engine timing; since it won't idle ground the coil spark wire while cranking the engine. Choke may be out of adjustment; when the engine is cold the choke throttle plate should close except for 1/8"; adjust as needed.

Have you checked timing? Do yo

Have you checked timing? Do you have a vacume leak at base of carb or intake?
Is the idle mixture set correctly?

Kurt

Guy
This seems like a catch 2

Guy
This seems like a catch 22. How can I adjust the timing if I cannot keep the engine running at the appropriate RPMs? Could you explain why I would ground the coil spark wire.
Ron

It doesn't have to be runn

It doesn't have to be running to check the base timing. You said it won't idle so I gave you a different procedure. Grounding the coil keeps it from sputtering. If you do it while at idle the temp. needs to be at operating temp and the idle speed set to spec. When you rev. the engine up to 1500 RPM the timing should advance.