Will moving the screw, retard timing on my 47?
 

I have the "G", 226 cu inch, SIX cylinder... It's been about a year and 3,000 miles I have put on the original stock motor.. I think I am getting "pre-detonation" at idle, the motor gives an occasion rattle noise at low rpms and runs rough, then smooths out at higher rpms.. I figure I need to adjust the points & give her a tune-up.. but in the meantime, can I move the screw up or down to retard the spark?.. it is a crab distributor.... :eek: The car sat for the last two months while I was getting the transmission rebuilt.

p.s. the engine will diesel (run on).. for a second at shut down

Thanks, WALT

Re: Will moving the screw, retard timing on my 47?
 

Screw up (clockwise) advances timing. Jack E/NJ

Re: Will moving the screw, retard timing on my 47?
 

Maybe carbon build-up in the cylinders. There are various methods of softening it so it can be pushed out the exhaust. MMO, water injection.

Re: Will moving the screw, retard timing on my 47?
 

The adjustment on the side is usually set with a timing fixture tool on the bench and then left alone. Points gap settings can also have an effect. Setting points to specs is usually the first thing then check the timing setting to get it all in sync. A steel rule can be used if following the procedure in the operator's manual or shop manual to check or adjust timing.

There may be something wrong with the advance flyweight unit or vacuum brake. It's best to check all that stuff for condition and smooth operation if you take the distributor off for service.

Re: Will moving the screw, retard timing on my 47?
 

Yeah... checking points is probably the first best solution.. .. I will put some MMO in the tank & a little in the crankcase..

Re: Will moving the screw, retard timing on my 47?
 

Running on after shutdown is usually due to carbon deposits on the valves or spark plugs. They glow after the ignition is shut off, and can cause "dieseling". Check and clean the plugs. I use RJ14YC plugs in my '47 because the longer tip burns clean. Also, be sure the carb idle adjustment isn't preventing the throttle plates from closing, allowing enough fuel to reach the cylinders after shutoff. Be sure that the idle speed isn't too high, and that the carb throttle shaft bushings are not worn, and the throttle linkage isn't worn.