I just pulled my plugs to see how they were doing and I snapped a pic of the line-up. From left to right: new (duh), T1, L1, T2, L2. They have about 4k on 'em right now. What do ya think of the color? Does this look normal? The engine runs great BTW. TIA

 

I would say just a touch lean. See the chacolate brown on the L1, thats just about perfect.

 

I would also say too lean. You really shouldn't be seeing all that white. If your engine is running good and strong, it might also be surging, which is caused by a lean condition. I lost an engine many year ago to this, and this is why I always run about 10% rich.

Spark Plug determination of Rich / Lean


NORMAL:
This is how your plugs should look after they've been used for a few miles. Nice, grey-brown deposits, lightly coated core nose. Plugs are ideally suited to engine, engine probably in good condition. Hmmm, lovely!

YOURS:
Overheated plug / Lean
Electrodes look glazed; core nose very white; few deposits. Plug is overheating.
Check plug temperature value, ignition timing, fuel octane rating (might be too low) and mixture setting (too lean). Rectify before piston rings break or valve faces burn.

 

Thanks! Hmm.... okay. So how exactly do I fix this "running lean" problem that I appear to have?

 

i believe the screw that controls the accelerator pump. in will give you a bit more gas. i'm carb illiterate so please don't bash me. other then that, changing your jets a size up.

 

Is it a stock Nikki?

 

More or less, well.... a little less. I have made the secondaries mechanical and I use a K&N filter. BTW, these spark plugs are NGK BR8EQ-14's.

 

Go slightly richer on the main fuel jets on the primaries, and mabye the secondaries.
.
There are four main fuel jets, two for primaries, two for secondaries. They can be accessed by removing the 10mm plugs just under each float glass and inserting long thin flathead screwdriver in there. I've always had best luck by removing the carb and pulling the air-horn off to do this. With all that on the car it's tough to get to though some people use toothpick to spear the jets and pull them out.

See what size jets you have. Small number stamped on each jet. Call Mazdatrix and go one size up. I would guess you have a non-stock exhaust system on the car? That would cause it to run a little lean. Also be sure air filter is clean. And check fuel pressure. And float level. Is fuel pump getting over 13.5 volts?

good luck!
-bp-

 

What does float level have to do with flooding specifically?

 

If they are too high, the fuel will run out of the float bowls, down the carb, and into the engine.

 

Running a BR9EQ might also help a bit I think... It's a colder plug, meaning it dissapates heat faster.

And while I'm on the topic of plugs, BUR9EQ (2nd gen plugs) would be a decent idea too. Or even better, BUR9EQP (Turbo II/3rd gen plugs)...