1959 Chris-Craft KFL Engine idling issues

[mlafrate]

I have a 1959 Chris-Craft KFL 3131 HP engine that has two Zenith carburetors. I rebuilt the carbs. Does anyone know if there is an initial setting of the idle screws, throttle etc. to begin tuning in the carbs? My engine runs fine but idles too fast (around 1300 rpm) and when it is at idle ( albeit fast) and running steady for a couple of minutes, it will eventually just die and stall out. Any suggestions???

[Moondocker]

Has the timing been set?

[mlafrate]

Yes the timing has been set. Thanks

[tuobanur]

The carb on my boat is a Zenith 9255 updraft. It required 3/4 turn out on the idle adjustment and 1-1/2 turns out on the main jet adjustment. You could also have a float problem.

[jim g]

The idle screw will end up between a half a turn to 1and 1/2 turns. I would start at 1 turn out. On the KFL the main jet should be fixed so you don't have to worry about that one. The throttle plate screw should be around 3/4 turn in form the throttle valve being fully closed.

Now the fun parts is getting the 2 carbs synced together so they are pulling the same amount of air at idle. Then do the fine adjusting with the idle screw.

http://www.amazon.com/Edelbrock-4025-Ca ... B00062YC2E

[Pete DeVito]

I posted this back in 2013.

"I have a KFL and if you pulled the carbs off the engine you had to remove the linkage. If you did not pull the carbs apart your problem is most likely the linkage is mis connected to one of the carbs. Remove the linkage and hook it to the proper hole in the carb lever. I can bet you have one of the carb's with the linkage correct and the other is in the wrong hole which is holding that carb open.
On the shaft that comes out of the carb it has the bracket where the linkage connects and most have two holes in them where the linkage can connect. On my KFL the linkage connects to the top hole on both carb's.
good luck!"

Now some additional information that will help you.
When working on setting the idle you should have a vaccum gauge handy. I have always used my old manual instrument and it works like a charm

My KFL idles at 700rpm and never skips a beat and it took almost an hour to tune both the carbs. When setting the carbs you have to have the linkage off and tune one at a time until you get them both adjusted. Once you get them adjusted the engine will smooth out and idle perfect. I have a service bulletin from Nov 1964 which gave great instructions but I can't seem to scan it. I would home that someone that has some old CC service bulletin's would take a look and share with us.

Don't give up...

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[tkhersom]

Hope this helps. (Someone else posted this on another tread that I copied)

[jim g]

Remember that Chris Craft idle spend is in gear. So you really want around 800 rpm out of gear.