Spark Plug Advice Needed

[Bewy]

No, not a problem with my procedure at all. The spark plug terminal is assembled by MSD, not the end user. And that was high resistance in one of the leads in the last set I assembled.

 

[bobscuda67]

Just an update on the tuning of my engine.
The spark plugs were changed one heat range hotter.

I replaced the metering rods with rods that are 8% leaner in cruise and power modes. It developed a lean bog just before the secondary opened.
So I replaced the orange step up springs with pink springs and the bog disappeared.
The full throttle jetting still has to be checked yet. There is only 20 miles on this plug but it looks better.

 

[Bewy]

Is the idle smoother with the hotter plug?

 

[bobscuda67]

Is the idle smoother with the hotter plug?

Yes. It's much smoother and I set the idle RPM at 650 because the 700 that the manual calls for is too high and it slams into reverse when set that high.

 

[Bewy]

That's great! I think many people are suffering unnecessarily with a rough idle because their plugs are too cold.

 

[bobscuda67]

I'll see how these plugs are coloring in another 100 miles and I might try to go another number hotter just to see if makes a difference.

 

[CFD244]

Great thread.