yamaha yz 250 iridium plugs

[Two smoker 2017]

Has anyone had any issues with iridium plugs in yamaha yz 250s. Iv had three in space of 6 hours of riding. It has a few hours riding then refuses to start and if it does it only runs for about 1 or 2 mins. Put the standard ngk back in and seems to be alot better first or second kick starter. Also have a kawasaki kx 85 and that runs fine with thease plugs in. Thanks in advance.

[William1]

Save your money. Precious metal electrode plugs were designed for vehicles where plug changes were very difficult and expensive to do, so more durable plugs were created. The 'extra performance' they provide on a bike is insignificant. Much cheaper and better, esp. on a 2S to simply regularly replace the standard type plug than to try and 'get your money's worth' from a fancy plug.

[Two smoker 2017]

Thanks for the reply i was changing them after every ride out becouse i got hold of a box of plugs for for free and when i ran out i tried thease. Im just going to do as you say and save my money and my right leg from trying to kick the thing up and stick to the standard plugs.

[arnego2]

I think the Iridium plugs are more finicky about running temps, oil ratio and such. Lugging is not their thing IMO 

[kxrob]

9 hours ago, Two smoker 2017 said:

Has anyone had any issues with iridium plugs in yamaha yz 250s. Iv had three in space of 6 hours of riding. It has a few hours riding then refuses to start and if it does it only runs for about 1 or 2 mins. Put the standard ngk back in and seems to be alot better first or second kick starter. Also have a kawasaki kx 85 and that runs fine with thease plugs in. Thanks in advance.

if you can't run the plug with out bike stopping you need to jet the carb 

[KDXGarage]

If you are using the correct model plug for your bike, then you have a problem with your motorcycle. This is not a cheap plug vs. expensive plug question / debate.

 

Can you provide more info? Thank you.

[bikedude987]

I've found that standard plugs foul easier.  Since I've been running the stock plug (iridium) I've not fouled.  Slightly hotter spark at the electrode keeps it clean.

[YZDOC]

I have the IMS ZipTy tank on my bike. I run Iridum BR8EIX and fouled maybe once. So, it's your bikes engine condition and jetting IMO. I have run from 1500 to over 5500 and never fouled on a ride. The time I did remember fouling, was right after unloading in the den, and I warmed up the bike, then got geared up, went to start in and no-go. So it wasn't even a trail side foul. 

So as William (mod) was saying is true, unless the plug is harder to get to, you could be wasting money. Your choice, 3-10 bucks for the different plugs.  

[subxero]

I have seen other people report similar issues when using the correct iridium plugs in a dirt bike.  

They are a waste of money either way.  

[bg10459]

I'm ashamed..... and proud, that I can't remember the last time I changed my iridium plug.  You guys saved $6

[rpt50]

There will be no detectable difference in performance between a BR8ES and any plug with an exotic electrode at normal change intervals.  I put in new plug every few months I suppose, or at least at top-end time.  In addition, on whatever bike I use for hare scramble racing, I put in a new plug before the start.  At $2.50, it's cheap insurance considering all the other expenses of racing.  It's probably all in my head, but it seems the bike starts a little faster with the new plug for the dead engine starts.

If your bike is fouling plugs, regardless of the brand or electrode, you either:

1. have the wrong heat range, or

2. need to re jet (or both)

Note that there is no "correct" jetting or heat range, but rather a range of possibilities.  For example, on my 125s, I use an 8 for the woods and a 9 for the track, and my jetting varies seasonally (temperature).  Some single track guys like to run 7s in 250s.