1923 roadster running bad need help
 

hello
my 23 has started to run bad i had the head gasket replaced and all the carbon cleaned, it idles fine but back fires ans loss of power. i do not have a compression gauge. i removed the no 1 plug and it was black with carbon. i have fire to all cycl. i have a rebuilt carb and good gas flow. what to i need to do from here
thank you
kevin

Re: 1923 roadster running bad need help
 

What was the reason to change the head gasket? Have you adjusted the carb to run a bit leaner?

Re: 1923 roadster running bad need help
 

the gasket had a leakes of antfreeze in the rt rear corner no leak into the oil
kevin

Re: 1923 roadster running bad need help
 

Did you make any changes to the carb mixture adjustment while doing your work? Spark plug wires re-connected correctly? Sounds like its running way too rich. When things like this stump me I slow it down and go back to the basics and recheck spark, fuel and air(mixture) especially when the car was running well previously.

Re: 1923 roadster running bad need help
 

Maybe check for a vacuum leak at the intake manifold. I imaging you remove the manifolds when the head was removed. Did you use a new manifold gasket? Did you tighten the nuts down nice a tight?

Re: 1923 roadster running bad need help
 

Bent a valve removing otr installing the head?

Re: 1923 roadster running bad need help
 

That happened to a friend. He and I were so careful and yet something touched a valve and it had to be replaced.

Re: 1923 roadster running bad need help
 

Is it back firing out the carb or exhaust? No 1 plug is the coldest so what do the rest of the plugs look like? If the rest are black from carbon, then yes running too rich. Which type/brand of carburetor are you using? Turn the spray needle down till the engine starts to stumble and open a bit. May need a bit more adjusting when you are driving. Are you using the copper crush rings or the fiber type 3 in one gasket on the manifold? Google "MTFCA checking for vacuum leaks"