Rough idles on Chrysler m440s

[OzzyToo]

So both engines are not idling properly. Stbd One has to idle around 2000 and will stall out at 1500. Port engine will idle at 600 - 700 but overheat quickly at idle but maintain temp at around 1200 - 1500 rpm.

Could timing be be an issue? Or the throttle be set wrong or even the fuel be too rich for stbd side?

cheers!!

ps both engines have about 2300 hrs on them

 

[northern]

Items. Dirty gas, raw water pumps may be worn out, carburetor may need cleaning if dirty gas.

 

[OzzyToo]

Items. Dirty gas, raw water pumps may be worn out, carburetor may need cleaning if dirty gas.

Thanks for the reply. We had the pumps inspected and they got the ok. Stbd cooling system is good. But it idles fast and is a hard start. Port side idles low but sounds good except it overheats at idle but maintains temp at 1200

 

[northern]

If you have to keep the RPM at 1200 to get adequate flow to cool it is either the pump or a blockage in the system.
Sounds like carbs to me if hard to start. If they are mechanical fuel pumps and original you might want to replace one and see if that helps.
If all original ignition wires, distributor, rotor and plugs time to replace them. Timing could also be out.

 

[OzzyToo]

If you have to keep the RPM at 1200 to get adequate flow to cool it is either the pump or a blockage in the system.
Sounds like carbs to me if hard to start. If they are mechanical fuel pumps and original you might want to replace one and see if that helps.
If all original ignition wires, distributor, rotor and plugs time to replace them. Timing could also be out.

Thanks for the reply. Some good suggestions. Definitely worth replacing the wires and plugs etc. Gonna be doing more troubleshooting today but will pick up wires and plugs etc and replace.

 

[DarkJester]

Don't forget the Caps and rotors for the Distributors. Notorious for hiding Ignition maladies.
If you have to idle that high to keep from overheating, and your "Pumps Got the Okay", you definitely have some sort of blockage or a leak.
Anything from collapsed hoses to clogged thermostats.
Start with the tune up stuff, and Fuel Filters, Fuel pumps, etc. Don't just throw a bunch of expensive parts at it, (Except for the tune-up).
It's a pantload easier to T-Shoot if there are known good items already installed.
Never underestimate the power of a good Visual inspection.
As a sort of "ear to the Ground" thing. Listen to your motors, do they sound like they are struggling? Are things just off sounding? Listening can tell you a lot.