Twin Cam plugs

[Nick dj]

My TC is due for a 18k service and they recommended changing the plugs at 12k but the cost was sky high.

The bike is running really well but they are 5 years old do I need to change?

If so I thought I might buy and fit them what do I need and where is best price wise?

Do I need an special tool to fit them?

Thanks Nick

 

[Bendy toy]

If the fuel consumption and performance are unchanged the plugs are probably fine. Personally I would check the gaps and put them back.

I changed my plugs at about 40K miles. The mains were fine but the secondaries were very hard to unscrew. I used a little copaslip on the base of the threads in the hope they come out more easily next time. I have some replacements to fit but will put the old ones back if they check out ok.

I use NGK DCPR8EKC plugs in my single cam, bought from a local spares factors from their NGK listing. They are single electrode (rather than twin) and cost about £4 each. There is probably a similar version for the twin cam.

So called twin spark plug should last about 2x as long as the single electrodes. But if they cost more than 2x the price and run the risk of seized threads is there any value to using them?

 

[Greenman14]

You do need a thin wall long reach socket to get the plugs out. And a puller to remove the coils is useful though it can be done with a couple of screwdrivers if you're careful. If you do buy a coil puller avoid the plastic type and go for something metal.

 

[Kenny Rodkiss]

Your mains will be shagged, your secondaries might just be useable though I doubt it.
The central electrode should be round not oval.
You will need four MAR8B-JDS and a thin wall long reach 14mm socket or equivalent plug spanner.
Here's a link to nick v in depth other plugs for your bike.
http://www.ukgser.com/forums/showth...the-only-spark-plugs-that-fit-the-DOHC-engine

 

[Mistacat]

I have fitted Denso IU24A Iridium plugs in my TC. £7.50 each.
I like the way that Iridium plugs stay in tolerance longer and have at least double the service life of the NGK MAR8B-JDS.
However They are not an identical specification, there are a couple of extra threads on these plugs and I was concerned that the threads would be exposed in the combustion chamber, causing pre-ignition and problems when removing the plugs.
I have not taken the head of a TC yet and cannot find a picture of a TC head (combustion chamber) with the plugs in.
To play it safe I machined the threads on the Denso IU24A plugs to replicate the NGK MAR8B-JDS plugs.
If anyone has a picture of a TC combustion chamber with the stock plugs fitted I would like to see it. (save having to machine my next set of plugs).

 

[Jorik]

2 years ego before installing Denso IU24 and NGK CR8EIX I removed those odd threads with the same reason.

https://www.dropbox.com/s/8sandhohmp6y8w8/plg1.jpg

 

[Wingless]

Best price I found recently for NGK MAR8B - JDS was 4 for £29.77 with free P&P.

http://www.ebay.co.uk/itm/FOUR-x4-G...378051?hash=item33adcf5483:g:OtAAAOSwf-VWXxpf

 

[Betty Swollocks]

Best price I found recently for NGK MAR8B - JDS was 4 for £29.77 with free P&P.

http://www.ebay.co.uk/itm/FOUR-x4-G...378051?hash=item33adcf5483:g:OtAAAOSwf-VWXxpf

I tried the iridium plugs last year after getting my bike re-mapped. The re-map went a bit strange and bike ran unbelievably rich for almost 4K miles. (32mpg average). Re-map done again and bike now 50mpg plus and feeling much better.
Anyways, I'm convinced the plugs are probably oiled up and fouled. Been looking online today for the cheapest set of original plugs and after an hour's searching got the same eBay seller. ( one eBay.de seller slightly cheaper but I'd prefer a uk seller)

But this seller won't deliver to Northern Ireland. So much for us being part of the U.K. and covered by Royal Mail at the same cost as the rest of you.
Gonna ring them in the morning.

Ps.... The iridium plugs I fitted ended up a 15mm socket an the plug I bought of eBay was useless. A mechanic pal ended up making a bespoke tool to fit them.

 

[fizzer]

i dont know where on earth they are coming from on that mate,posting to northern ireland is the same price as posting next door if using the post office .i think some parts of the highlands in scotland have restictions but thats it i think.

 

[Betty Swollocks]

i dont know where on earth they are coming from on that mate,posting to northern ireland is the same price as posting next door if using the post office .i think some parts of the highlands in scotland have restictions but thats it i think.

Fizzer, I phoned them today, the guy was apologetic and told me it was a default that eBay had put on the listing.
He changed the settings there and then. I ordered again after a minute and they are en route.

Best price I could find on the net!

 

[AberdeenAngus]

Fizzer, I phoned them today, the guy was apologetic and told me it was a default that eBay had put on the listing.
He changed the settings there and then. I ordered again after a minute and they are en route.

Best price I could find on the net!

Well done for chasing them up. Had a similar experience with sellers that try to charge extra for Aberdeen, as it is 'highlands and islands'...which it isn't.