Iridium spark plugs !

[gonzo 2,211]

Have noticed some on here have changed to the iridium plugs ! Why ? What’s the advantage! Answers please ! Still waiting for my CRF to be delivered ! 🥱

[Andy m 23,546]

Iridium has a higher melting point. To do the St.Greta stuff the designers increase compression ratio and lean off mixtures, which means more heat. A softening electrode will be worn away by spark errosion.

 

On cars they also buried the plugs so need them to last 100000 miles. On bikes they take the ****, Guzzi claim they only last 6000 miles which is more likely a scam to increase service revenue. There is no way they wear ten times faster than in a car. The only technical reason to change them is them rusting into the head. Copper slip is cheaper than new plugs.

 

Andy

[alhendo1 3,046]

I can see the point of them for bikes like my 500x which is half a day out to get to the plugs....my car , a Hyundai i10 is supposed to run them...they're a doddle to access so I just change them every other service with normal plugs and the car runs fine....

[Jamesc 3,655]

I had a Subaru flat 6 that wasn't fun at all to change the plugs.

 

Don't forgot to reduce the calibrated torque wrench setting by 20% to account for the copper slip!))

[skorpion 945]

6 hours ago, gonzo said:

Have noticed some on here have changed to the iridium plugs ! Why ? What’s the advantage! Answers please ! Still waiting for my CRF to be delivered ! 🥱

NC750 plugs are iridium as standard oem.

Edited April 8, 2023 by skorpion

[Steve Case 955]

Even if you dont change them, take them out and inspect them just to prevent them becoming unremovable.

[Rev Ken 6,340]

On my CBF I fitted iridium and 40,000 miles later on (my son has 'inherited' it) they are still fine. Subjectively the bike seems to run more smoothly at tickover and start more easily when the battery was failing, slowing down the cranking speed, but that might have been my imagination. I like them!

[gonzo 2,211]

On 08/04/2023 at 17:06, skorpion said:

NC750 plugs are iridium as standard oem.

So I wonder if all new Hondas have them ! Inc my yet to be delivered CRF 300 L ? 

[skorpion 945]

2 hours ago, gonzo said:

So I wonder if all new Hondas have them ! Inc my yet to be delivered CRF 300 L ? 

 

Yes.

NGK 91064 SIMR8A9 

https://www.manualslib.com/manual/2146379/Honda-Crf300l.html

[Defender 3,837]

A word of caution here folks, DON'T ignore them if your mileage falls short of the advised requirement, a friend of mine had a spark plug fail, the electrode fell into the cylinder and damaged the piston and valves. Although the bike was out of warranty, the manufacturer supplied the parts, including a replacement spark plug, my friend had to pay for the labour, not cheap, but far more than a new set of plugs and fitting is?!