Did I changed my spark plugs too soon?
 

Here's the pics of OEM spark plugs, they have 24K miles on them:

http://farm7.static.flickr.com/6084/...239c5b71_o.jpg
http://farm7.static.flickr.com/6162/...f6529d68_o.jpg
http://farm7.static.flickr.com/6191/...fbb75bfc_o.jpg

Manual says replace at 37.5K for normal conditions and at 35K if "unique conditions apply". I do quite a bit a short trips so I guess mine should be closer to 35K.

Excepts strange deposit (what can it be?) they look good to me, problem is it was looong time I looked at used sparkplugs and I can not really judge how bad they are :).

Premix using LC20 (1oz per 1 quart of oil) and FP Plus (1 oz per 10 gallons of gas).

Car had 75K when they was changed, car started to have minor issues with staring when cold (took quite a few cranks to start) and had a really nasty exhaust smell when that was happening so I replaced coils with BHR system and changed plugs as well.

Alex

1oz of premix per quart of oil? How do you premix?

Details http://lubecontrol.com/lube.htm
Premix is probably not correct term in case of LC20.

You didn't premix then!

That nasty stuff you put in the engine's oil may very well be the reason why you have weird deposits on the spark plugs.

As I said I'm premixing with FP Plus - http://lubecontrol.com/products_fuel_power.php

Here's my story, I have this car for almost 50K now and had to take it to Mazda for decarb 3 times:
1) ~40K (loss of power etc)
2) ~45K (same as above but much worse, got new engine)
3) ~50K , no kidding - newly installed engine developed same issue in just 5K! noticeable loss of power again

Notice 5K interval.

Since I got my car NOTHING changed - same commute (9 miles one way, 6 of them on the freeway) and occasional 20/30 miles drives once a months or so.

I was told by Mazda tech that decarb is needed that often because of my short commute and perhaps the way I drive. I must say that my other cars (Hondas) was totally fine with this :)
Anyway I got tired of this and looked around and read about this FP Plus / LC 20 somewhere on the http://www.bobistheoilguy.com

Since I start doing that LC20 / FP Plus stuff mix/premix - 25K miles later I never ever had that power lost, car is freaking strong as it was when new engine was installed. That just a cold fact.

I'm wondering if someone has pics of spark plugs with same or close mileage, it will be interesting to compare.

Found similar threads with pics:
https://www.rx8club.com/showthread.p...ug#post3819400
https://www.rx8club.com/showthread.p...lug#post941102
https://www.rx8club.com/series-i-tech-garage-22/read-my-rx-8-spark-plugs-please-176447/
https://www.rx8club.com/australia-new-zealand-forum-37/hesitation-high-rev-found-solution-87376/

Look's like mine are OK.

Fp60 is kind of premix, but at 1 ounce to 10 gallons you will probably hardly feel it. Quite a lot of people use it but they also include a jaso-fc/fd 2 stroke oil at about half an ounce per gallon or less for some people. Give it a try using some 2 stroke oil you should notice a difference.


Hopefully your changing your oil more frequently than that lube site suggests when you use that oil additive.

wait, let me get this straight, you mixed fp60 into your engine oil ?

ok ...

I never use fp60 b4 but if you mixed it into your engine oil, then what you did was wrong ...

and those plugs don't look all that bad at 27K miles.

what you need is coils ... all 4 new ones. change it when you change spark plugs. yep NYCGPS said it. :) if you want to save a few bucks, there are places online where you can get all 4 coils for less than 100 and all 4 plugs for less than 60. ;) (Just noticed u got BHR already, ignored the last sentence)

Anyway, Rotten egg smell could be a sign of "dead cat", you're at 75K miles so u might want to have that look at b4 ur warranty runs out. a new stock cat is really expensive

After all the hurdles I'm very happy with the way my car runs right now :)
I test drove brand new RX-8 few months back and mine was just as powerful (which is subjective of course but still).

I change it at 4.5/5K miles.

No, I'm not using FP60 at all, I'm adding 1oz of FP Plus for each 10 gallons of gas every time I refill and also add 1oz of LC20 to each quart of oil when I add/change it.

Plugs had 24K miles on them so is coils.
I replaced coils with BHR setup and installed new plugs - right now car starts right away. I'll wait for colder weather to make final conclusion but so far so good.
Bad smell is gone too.

The only outstanding issues is exhaust smell in the car saloon after hard driving hard for some time, but I'm not sure this is really and issue as it happened few times and could be just wind direction :)

Cat was replaced at 50K - at the same time I got new engine.
Oaktree Mazda of San Jose was kind enough to replace it along with many other parts.

As we speak there's nothing original left in my car (except tranny and clutch) - every single piece was replaced.
Most of that work was covered by warranty:
- new engine
- coils & plugs
- catalytic converter
- coolant reservoir with faulty sensor (broke again already)

Later I did following:
- braking system overhauled (new rotors, pads, steel lines fluid etc)
- cooling system overhauled (BHR radiator, silicone pipes, thermometer, water pump etc)
- new Bilstein shocks
- lost's of small items

Hope to drive at least 2-3 years without any major work.

start premixing and stop using unkown additives and it will work just fine... as long as you're using the right pcm flash.

The deposits on those plugs don't look bad, compared to some I've seen. Did you check the electrode gap? Mazda specifies an acceptable range. Electrode erosion would tell you if you changed them too soon...

Alex I meant fp plus I just saw fp60 on the link you gave and typed that. Either way you should add in some 2 cycle oil with it I think since the 1oz to 10 gallons isnt much at all. I bet you feel a difference in the car if you add a half ounce(or less if you want) of jaso-fc/fd 2 cycle per gallon of gas.

just put 6-8 oz of 2 stroke oil to a full tank and call it a day/