NGK MAR8B-JDS Spark Plugs (Twin Cam)

[David.]

At 12,000 miles, I will be changing the Spark Plugs on my 2012 Twin Cam.

BMW want £12.13 each, however, OPIE do the Plugs for £8.61 each (4 pack), http://www.opieoils.co.uk/p-69380-ngk-s ... -8765.aspx.

My local BMW Dealer agreed, they are exactly the same except the box & the price.

[Catfunt]

I had a lengthy conversation about this with the chaps at NGK in Hertfordshire. I wanted to use an iridium equivalent but 'apparently' there isn't one. The only issue 'apparently' is the short length of unthreaded section closest to the firing end which is there to prevent the possibility of a fully threaded plug becoming carbonised and thereby preventing it being unscrewed. I was (am) a bit dubious but I bottled it and went for the OEMS (£48!!!). I would be very interested in a link to the OPIE ones :-)

[David.]

Found this thread on UKGSer, "MAR8B-JDS are not the only spark plugs that fit the DOHC engine."
http://www.ukgser.com/forums/showthread ... +MAR8B-JDS



I would agree with you about the thread length, I managed to strip a thread on my 1981 Yamaha XJ650 whilst removing a plug, ended up having to remove the head & have a helicoil fitted.

Please see link in OP for OPIE.

[David.]

At 12,000 miles, I will be changing the Spark Plugs on my 2012 Twin Cam.

BMW want £12.13 each, however, OPIE do the Plugs for £8.61 each (4 pack),http://www.opieoils.co.uk/p-69380-ngk-s ... -8765.aspx.

My local BMW Dealer agreed, they are exactly the same except the box & the price.

Changed the Spark Plugs today, confirmed that the OEM ones fitted from new were exactly the same as those now fitted by myself.

[Catfunt]

I've got to admit that fresh plugs really made a noticeable difference. As I got closer to the 12k service, I had noticed an increase in occasional hesitations at small throttle openings and a slightly erratic idle. New plugs and everything was back to perfection and is still so at 16k miles

[David.]

My RT has done 10,700 miles, decided to change the plugs whilst the Panels were off, rather than wait until next year & have to strip things down after only 1,300 miles.

[wsmcycle]

what panels preclude spark plug access?

[David.]

what panels preclude spark plug access?

The Main side panel needs to be removed to access the Secondary spark plug.



This video may also help to show why the panels need to be removed:- https://www.youtube.com/watch?v=2UHU4ZQ2C_Q

[guest2360]

The solution is an LC.  Plugs are half the price and no panel removal necessary.

[Levisp]

Half the number too.

[guest2360]

Half the number too.

Making them half the price.

[Levisp]

Silly me.

[David.]

At 12,000 miles, I will be changing the Spark Plugs on my 2012 Twin Cam.

BMW want £12.13 each, however, OPIE do the Plugs for £8.61 each (4 pack),  http://www.opieoils.co.uk/p-69380-ngk-s ... -8765.aspx.

My local BMW Dealer agreed, they are exactly the same except the box & the price.

As sold by MAX BMW.

[David.]

I found the plugs here for £29.85 (inc. P&P).

https://www.ebay.co.uk/itm/221959378051 ... EBIDX%3AIT

[David.]

At £9 each Nippy Normans currently seems to be the best price, https://www.nippynormans.com/r1200-adv- ... 10-to-2013