Plug Caps

[liamstears]

So my plug caps resistance all measure quite differently so would like to replace them but stock are not cheap

Is there an NGK alternative that fits well?

 

[FinalImpact]

What values did you get and why are you looking? 10k +/- 500 is likely fine although IIRC mine were much closer than that.
Simply pair the closest ones on 1 & 4 and 2 & 3.
I've seen some of the plugs be off more than 500 ohms... Most are roughly 5k ohms but some are 4k so....

 

[liamstears]

Thanks for the reply

Mine are between 8k and 11.5k so quite a difference really

Got bad vibes and a lot of people point towards spark so thought I would try this route...

 

[FinalImpact]

You might just roll the dice and grab coils, wires, caps off ebay. Cheaper than new caps alone.

USD paid $30 shipped.
One observation about the cap to ceramic resistor is that I found a cap had overflash molding deep inside that when assembled correctly, (resistor, spring, plug lock) the resistor did not make a good connection to the cap.

Looking deep inside I saw black flashing. So glued some abrasive paper on a dowel and spun to remove the flashing. Cleaned with MAF cleaner and the cap in to cap out then measured exactly what the resistor measured.

Something to keep in mind if R is too high when measuring assembled cap!

 

[blahblahblah]

I recommend that you take a look inside the spark plug terminal of your caps and see if anything is corroded. It should be nice and shiney. If it isn't, replacing the caps with the factory Yamaha items is best, IMHO. A bit pricey, I know, but anything purchased on eBay will likely have the same problem. Even my bike, which has always lived in sunny Southern California, had corroded spark plug caps.