Suppressor caps

[Valley boi]

Just giving the bike a clean while it was ticking over and heard arcing so checked the leads/plugs and noticed arcing between the bottom of the caps to the head but the rubbers are a good tight fit over the plugs. All 4 are the same, any info be good as got mot soon. Cheers

[BBROWN1664]

It shouldnt be an MOT failure but does sound like your caps are focced. Get some new caps and trim 5mm of the leads when you fit them.

[Valley boi]

Which are the best caps to get ?

[darrsi]

Ebay NGK SDO5F


Tried and tested, and a damn site cheaper than OEM.

[darrsi]

Your choice, go for OEM if you want 

[Valley boi]

They look like the ones on the bike already 😳

[darrsi]

They look like the ones on the bike already 😳

They are, they're OEM ones.


Lots of us use the NGK type, and they work just fine.


https://www.ebay.co.uk/itm/4x-NGK-Resistor-Spark-Plug-Cap-SD05F-black-8022-/232610727266?_trksid=p2349624.m46890.l49292

[Valley boi]

Right I Just bought them, what about plugs.

[darrsi]

You're gonna have to ignore the price, and remember how much you just saved on the caps. From experience i can promise you this is the way to go. They are generally more throttle responsive and will probably outlive the bike.

https://www.gsparkplug.com/1x-ngk-iridium-ix-spark-plug-cr8eix-4218.html

[darrsi]

Don't buy plugs from Ebay, i learned that lesson the hard way.

[Gnasher]

You're gonna have to ignore the price, and remember how much you just saved on the caps. From experience i can promise you this is the way to go. They are generally more throttle responsive and will probably outlive the bike.

https://www.gsparkplug.com/1x-ngk-iridium-ix-spark-plug-cr8eix-4218.html

They do absolutely nothing for performance, this debate was put to bed years ago. 

Platinum and Iridium plugs were developed to increase plug service life, to keep pace with advances in engine materials and oil tech, pushing service intervals of cars to 20k plus mileages.   They do that by being harder, they resist wear from spark erosion much better than nickel alloy which is what standard or what's referred to as copper core.  But copper core perform better than either Platinum or Iridium they just don't last as long and as they fail the start to misfire more.  Plugs with dual or multi electrodes were developed for the same reasons, i.e. service life, Platinum and Iridium perform better, the latter being better the the former of the two. 

Yes they will last longer no they won't increase throttle response, its placebo effect.  All that is happening is the old plugs were starting to breakdown (misfiring) changing them with standard plus will give you the same result.   

[Gnasher]

Don't buy plugs from Ebay, i learned that lesson the hard way.

Why not?  There are many dealers/sellers on ebay who deliver an excellent service. 

[Valley boi]

Just bought some oem plugs, that's what yamaha recomend so I'll give them a go.

[darrsi]

You're gonna have to ignore the price, and remember how much you just saved on the caps. From experience i can promise you this is the way to go. They are generally more throttle responsive and will probably outlive the bike.

https://www.gsparkplug.com/1x-ngk-iridium-ix-spark-plug-cr8eix-4218.html

They do absolutely nothing for performance, this debate was put to bed years ago. 

Platinum and Iridium plugs were developed to increase plug service life, to keep pace with advances in engine materials and oil tech, pushing service intervals of cars to 20k plus mileages.   They do that by being harder, they resist wear from spark erosion much better than nickel alloy which is what standard or what's referred to as copper core.  But copper core perform better than either Platinum or Iridium they just don't last as long and as they fail the start to misfire more.  Plugs with dual or multi electrodes were developed for the same reasons, i.e. service life, Platinum and Iridium perform better, the latter being better the the former of the two. 

Yes they will last longer no they won't increase throttle response, its placebo effect.  All that is happening is the old plugs were starting to breakdown (misfiring) changing them with standard plus will give you the same result.

Throttle response felt better to me, and that's really all that matters.
And you've gone to all that trouble saying Iridium aren't better but then in the same breath explain how standard one's fail? 

[darrsi]

Don't buy plugs from Ebay, i learned that lesson the hard way.

Why not?  There are many dealers/sellers on ebay who deliver an excellent service.

Because I bought moody ones from there that failed after one month.
The company I suggested are not only totally legit but are normally a better price anyway.