carbon on plugs

[noah4009]

I have a 1971 55HP Chrysler. Since November I been working on this motor. I did everything possible that can be done to it. Thanks to Frank and you guys it is up and running. All adjustments are fine. Ready for a water test. I did the de-carb per another thread. Seafoam in carb, seaform in pistons. And it smoked, smoked, smoked. Before and during de-carb. This I did a couple of times. Went thru at least 4 set of plugs during this de-carb. Well after warming up the smoke is minimal. But if you remove plugs, bottom more then top has lots of black carbon on it. You can rub with finger and finger turns black. Do I do another de-carb? Do I just leave alone and wait till on water to see if that burns off? I mix oil/fuel 50:1 Is too much de-carb (seafoam) not good? Any suggestions will be greatly appreciated.

 

[steelespike]

Re: carbon on plugs

Idle may be set a little rich but better too rich than too lean.Get her on the water. Properly warmed up and give her a run.Be sure the throttle plates are syncronized,Idle speed about 700-800 in gear, adjust the screws warm in gear unrestrained.

 

[noah4009]

Re: carbon on plugs

Idle may be set a little rich but better too rich than too lean.Get her on the water. Properly warmed up and give her a run.Be sure the throttle plates are syncronized,Idle speed about 700-800 in gear, adjust the screws warm in gear unrestrained.

I tried adjusting the idle in neutral. The lowest RPM I can get is 1000-1100 in neutral. Any lower and engine dies. I read in other threads that the idle should be about 750 RPM. So are you saying that the idle they are talking about at 750 RPM is set in gear and not neutral.

 

[steelespike]

Re: carbon on plugs

Not a Chrysler expert but this is from an aftermarket ser. manual.
800-900 in neutral,700-800 in gear.You might want to verify the tach is accurate. Be sure the carbs are synced,double check timing and point gap if applicable. .0015 variation in adjustment will change timing 1 degree.
Magneto ign. is .020.All others .015.

 

[noah4009]

Re: carbon on plugs

Will do, thanks

 

[CharlieB]

Re: carbon on plugs

If the motor refuses to idle down then recheck your ignition timing.

Ensure WOT is set by the book, then start looking at idle timing, chances are your idle timing is too advanced, raising idle speed.

 

[noah4009]

Re: carbon on plugs

If the motor refuses to idle down then recheck your ignition timing.

Ensure WOT is set by the book, then start looking at idle timing, chances are your idle timing is too advanced, raising idle speed.

The motor will idle down but it dies when it goes below 1000 on my tach. Seems like when the idle is 1000RPM or lower, its just to slow and it shuts off. Tach is original and old.