Ckforker

Both my Trailing plugs seem to be very lean, whereas the leading seem to be be normal.

it runs really well, but decided to change plugs since they were 4 years old.

one, any concern with these?, and two if something needs to be done, would it be to tweak timing?
Thanks

Trailing

Trailing

Leading

Leading

LongDuck

Four years old, but how many miles? Also, what engine and intake mods? What oil are you running? Pre-mixing? Without knowing, those look fine and I'd leave them in unless you're just doig PM, in which case, also replace your Cap and Rotor, Plug Wires and air filter, too.

The leading plugs have big, wide holes to fire through, which means they will pick up a lot more fouling and oil marking over time, making them a little darker. The trail in plugs fire through pin holes by comparison, so they usually come out looking more like what you'd expect. If you're not changing your engine oil and filter regularly, plugs will look like yours inside of 1,000 miles.

There are some who change plugs frequently hoping for best performance out of old ignition components. Truth be told, at the horsepower ratings these engines put out, those plugs work fine and will continue to work fine for many more thousands of miles, but plugs are cheap (*even at $6-7 each!).

Ckforker

Sorry for leaving out the info. They have about 6,000 miles on them, about 70/30 city to highway. It's a stock 12a, except a RB header which is about 500 miles old, if that.

No pre-mixing, OMP is still pumping.

The oil gets changed every 6 months, since I'd never hit the 3k OCI.

Sounds like it's a non-issue at this point.

j9fd3s

iTrader: (3)

the plugs look really good actually