aftermarket plug caps ?

[Carter]

Hi, traced the poor running to grubby carbs, all cleaned and set back to factory settings but found a duff plug cap then. Had a fright when I saw the yamaha prices so wondered if anyone knows of an aftermarket 10 ohm cap that will do the job. Failing that it's the breakers.
NGK did do a cap which probably would've been the right shape and size but looks to be discontinued so any ideas would be helpful.
Thanks
Nick.

[Bretty]

I bought the straight NGK ones around the middle of last year off internet. They made quite a difference on my tired bike.

I bought them online only a couple of quid each:
1x NGK Spark Plug Cap SD05F-B - 10-12mm

[Adam2201]

Yep, I've got the NGK ones on mine - only difference is that they aren't right angled at the top.  If you have one of the faster, red models you can get the caps in bling-bling matching colours as well:  http://www.ebay.co.uk/itm/1x-NGK-Resistor-Spark-Plug-Cap-SD05F-red-8238-/230778918900

[Carter]

Ah thanks, I wasn't sure about using those as they're 5 ohm resistance but it sounds as though you're happy with them so will give them a go.
Was quoted 44 quid for a pair from yamaha and told they don't sell them single.

[darrsi]

I've had the NGK caps on my bike for years, they work just fine and at a fraction of the cost of being mugged off.

[Carter]

Thanks again for your replies, had a read up on ignition and resistors and it appears the spark can be made to last longer by using resistors and this helps burn the fuel more effectively. Apparently, the fuel/air mix can stop burning as the piston goes down and compression drops after the initial bang near tdc. There's an issue with interference without them too which can play havoc with ecu's and telly's etc. The resistor spark plugs are usually 5k ohm , same as the caps which makes 10k  and a clean burning engine.
My only problem now is I've seen the nice red champion caps too and can't decide what to get

[darrsi]

Thanks again for your replies, had a read up on ignition and resistors and it appears the spark can be made to last longer by using resistors and this helps burn the fuel more effectively. Apparently, the fuel/air mix can stop burning as the piston goes down and compression drops after the initial bang near tdc. There's an issue with interference without them too which can play havoc with ecu's and telly's etc. The resistor spark plugs are usually 5k ohm , same as the caps which makes 10k  and a clean burning engine.
My only problem now is I've seen the nice red champion caps too and can't decide what to get

You read too much. 


The NGK are tried and tested and work well, why deviate from what we just told you?
They do the NGK in red too, 'cos that's what i've got on my bike.

[Carter]

You can never read too much
Got the red ones on order now to match my paintjob.
Cheers for the help.