Steimied, Stumped and Puzzled

[dr1979-340]

Restored both a '79 and '80 440 Drifter.  Both completely gone through with new rings, gaskets and seals.  All new fuel lines, new fuel pump baffles, carbs cleaned, new jets, etc.

I put new CDI and ignition coil on the '80.  Original CDI and ignition coil on the '79.

They both develop a loss of power and run on one cylinder after running a while. I had the '79 out Saturday and put 27 miles on it.  It would run fine and then intermittently lose spark on one cylinder.  It would come and go.  I took the plugs out when I got home and one was darker than the other indicating that was the plug losing spark.

The troubleshooting in the table goes over a some things to look for.  I'm not sure if they are listed in the mostly likely to least likely order. 

Since both the NGK BR9EV and BZ9EV are obsolete I've been using NGK BR9ES spark plugs gaped to .024 which the manual calls out.

Can the Pulser Coil go out and back when hot?  That is the only part that hasn't been replaced on the '80.

Any insight would be greatly appreciated.  Thanks, Dale.

[kawhead]

have you checked the plug wire ends,there are some issues there

[dr1979-340]

I put new spark plug caps on but will have to check them.  Thanks.

I may run out of snow for field testing the machine.   

[Mark Hill]

 Since both motors were removed from chassis and have the same issue maybe you should check your ground wires .

[jimvw57]

Since both plugs fire at the same time, it is doubtful it would be a pulser coil. Id look at the external coil, and more likely the plug ends. Make sure they are not the resistor ends, you don't need them if you are running resistor plugs and that could cause some issues. too much resistance