Optra OEM Spark Plug after 40,000km

[Cbx750p]

Here is what the spark plug look like after 40,000 km ! Took them out and found that the gap have increased to some 1.3 mm. Standard is 1.0 > 1.1 mm.

 

Notice that the V group centre electrode have already been worn bad ! The ground electrod also have some wear. Adjusted the gap back to 1.0 mm and would expect another 40,000 km. Need to inspect them earlier, i.e. at 20,000 km interval this time.

 

Notice fuel consumption have improved almost immediately. Guess the manual is right about changing the plugs at 20,000 km interval. Only disagree with the need for new plugs. Simply adjusting the old plug should be good enough!

 

CBX

Edited January 22, 2006 by Cbx750p

[Atlantis_boi]

Bro, ur plugs looks kinda black. Are those carbon build ups? I changed all my plugs @ 40K & they r not so black.

[Cbx750p]

Agree partially but there was no misfiring ! The increased gap, probably contributed to the "darkening" of the plugs and decreased fuel consumption. If you look carefully, it is not black but dark brown ! In ideal case, it should be "brown"

 

If the plugs were to be shorted, i.e. become really black, then I would definitely be in trouble ! Would not be able to start the car when the plugs are shorted !

 

CBX

Edited January 22, 2006 by Cbx750p

[Atlantis_boi]

Oic. Prob u need to stretch ur engine once in a while to clear off those carbon buildups.

[King]

i kaisu, i change every 10k or even 20k

[Cbx750p]

Yeah...sure...stretch the engine ! Like where can you do that really in Singapore ? Speed trap every where !

 

Once in a while, would sneak up to Malaysia for a good spin ! Last spin to Thailand...with top speed at 190kmph...enough lah !

 

The plug condition is acceptable for covering 40K km ! After the good scrub, the plugs pretty okay !

 

CBX

[Clusterbx]

The Optra stock plus are NGK 6E-11. These plugs are not really expensive, about $10 or less only.

 

Friends had told me to save money by sand papering them every 10k km and it'll be as good as new.

 

Afraid that i'll sand too much away and cause a performance or FC issue..

So i always changed them at 10K km, as i'm not tech-savvy, it's not that i'm rich or what.

[Cbx750p]

Yeah...I know what you mean but owning a car in Singapore, every cent counts ! I also hate the idea of throwing away a perfectly working item like them spark plugs ! I cleaned my and found the FC back to normal again...now I getting about 12 to 13 km per litre compared the last time of 11 to 12 km per litre ! Nevertheless, for the less tech savy guys, changing a new set of plugs would actually do but be reminded that you must check that the gap is correct. Sometime the plug or maybe two may get a different gap due to production or handling so you will get different spark from the bigger or smaller gapped plugs. Nothing technical but just simply using a $4 feeler gauge between the centre and ground electrode and making sure it between 1.0 to 1.1 mm !

 

CBX