460 King Cobra Cold Start Problem

[tmakows]

I have a 1991 23.5' Chris Craft Concept that has a 460 King Cobra engine in it. I am a relatively newer boater, and not very mechanically inclined. I'm trying to see if anyone might be able to help shed some light on a problem that I noticed last boating season. Here's the issue I'm having:

On a cold start, the engine stalls out alot. Basically, my starting process is as follows: I pump the throttle back and forth a couple of times, and then push the neutral button in and move the throttle open about a 1/4 of the way. I then turn the key to start the engine. This always starts the engine. However, as soon as I put the throttle back into the neutral position to just let it idle, it always stalls out. My fix to this last year was to just the let the boat idle pretty high for 3-5 minutes prior to putting it into neutral. This allowed the engine to warm up and then it was good to go. Once the engine was warmed up, it allowed me to start the boat in neutral without giving it any gas and it never stalls out.

Does anyone know what could be causing this problem? I have had a few people tell me that it could be my choke needs to be adjusted. Someone told me it sounds like the choke is running too lean?

Again, I don't know very much about this type of thing, so any feedback/experience would be greatly appreciated!

 

[a70eliminator]

Re: 460 King Cobra Cold Start Problem

It's a carbureted motor you'll have that, mine does the same thing, you starting technique sounds perfect.

 

[Juniinc]

Re: 460 King Cobra Cold Start Problem

The choke probably needs to be repaired or adjusted.
set too lean?
could be sticking.

 

[HT32BSX115]

Re: 460 King Cobra Cold Start Problem

Howdy,


Your 460 has a Holley 4160 installed on it.

It's also got a electrically operated automatic choke.

Basically, when the engine is cold, the automatic choke plate is closed by the spring pressure in the electrically heated "actuator"

When you start the engine (and you "pump" the throttle) the choke also induces a rich mixture (while the electrically heated element is slowly opening the choke) By the time the choke completely opens the engine is probably done warming up.


If the choke plate is NOT closed when the engine is cold, (and you want it to work) it needs to be adjusted. You should be able to observe the choke plate opening slowly if you watch it.


Now having said that, if you only boat in warm weather, you might not need "choke" "action" at all.......... Up here in the NW, I only boat in "summer" type weather. I completely disabled my choke altogether and I do exactly what you do....I did it on m previously installed 460 and I also disabled it on my 454.


YMMV,


Regards,




Rick

 

[tmakows]

Re: 460 King Cobra Cold Start Problem

Thanks for the feedback guys. Do you feel with my starting procedure that I am reving the engine too fast and for too long? I have to keep it above 2000 RPM's for 3-5 minutes to get it to warm up. I'm just afraid that is possibly bad for the engine.

 

[HT32BSX115]

Re: 460 King Cobra Cold Start Problem

It's never sounds all that good to "rev" a cold engine.........

But stationary auto-start generators routinely start and run at rated RPM from a cold start up for thousands of hours with no apparent ill effects.....

Your engine shouldn't require running at 2000 RPM to keep it running after a cold start up though.... 1000-1200 should be more than enough......

If it won't run at above rpm, you probably need to readjust the idle mixture a little richer (after the choke opens)

Also, if the choke is not closed at all before you start up(cold) , then it probably either needs to be repaired or adjusted too...