Changing plugs on a Rocket

[roadbosstx]

Yes, I am still a newbie and don't yet have a manual. Do I need to remove the fuel tank to change the spark plugs? If not, any advice on how best to access those little ignitors? Thanks!

[Steve Block]

Welcome roadbosstx,

No need, just remove the single bolt that secures the tank to the frame at the front of the bike near the headstock and the tank hinges from the rear. There is a small tank stay secured near the ignition coils that you simply un-clip and "plug" into the bolt hole that holds the tank up.

There's enough room to get to the plugs, but you will need a deep reach 12mm plug spanner as they are recessed quite a bit.

Cheers
Steve

[roadbosstx]

Thank you Steve Block! I like to do my own wrenching when at all possible. My personal opinion is that the more we understand about our machines, the more we can be 'at one with them' on the road.
Do you or anyone have a reccomendation on what plugs to use? My bike is completely stock.

[Steve Block]

I don’t know if other R3 owners are passionate about a specific plug per se, since the R3 motor has two plugs per chamber I guess, it may be a little academic what type of plug is used.

I personally run on Iridium plugs as they are “claimed” to produce a more efficient spark, which may help a cleaner burn (hopefully leading to better fuel economy and efficient engine running), at least that’s the theory… (opps, I mean sales pitch)

http://www.spark-plugs.co.uk/pages/t...park_plugs.htm

Cheers
Steve

[roadbosstx]

Thanks again, Steve Block. I run NGK Iridiums in my other bikes for the reason stated in your reply. Who knows! Regarless, do you or anyone know the plug number. I want to purchase (order in my case) the plugs prior to removing the old. Thanks gain!

[Steve Block]

The plugs listed in the manual are : NGK DPR7EA9.

The iridium tipped plugs I've fitted are : NKG DPR8E1X-9.

Although the numbers are similar the differences are:

D = 12mm (plug spanner size)
P = Projected Center Electrode Insulator
R = Resistor Type

7/8 = Heat Rating (i.e. how hot can the plug burn at)

E = 19mm Thread reach (how far down into the cylinder it will go)

A = Special Design
IX = Fine Wire Iridium Centre Electrode

9 = 0.9mm Gap

The key issue is the first letter (D) which denotes the plug size, and I would say the fifth letter (E) which denotes the plug reach. Get any of those wrong and the plug either won't fit or work properly.

Torque the plugs down to 20 Nm.
This is the same for all three Rocket variants.

More info here:
http://www.spark-plugs.co.uk/pages/technical/ngkjpg.htm

Cheers
Steve

[TRIIICK]

Have you noticed a big difference in performance with the NKG DPR8E1X-9's. Is it worth the extra $54.00 you pay..??

[Steve Block]

If I'm honest, I couldn't say. I know on smaller displacement bikes I've had, it did make the motor smoother and seemed to make the acceleration a bit more lively.

With the tractor sized engine of an R3, it may be totally wasted. I'm not so sure I'd buy them again when it comes to replacing them, as you say the price difference is significant. I suppose my incentive at the time I got them, was to try and help to get the best poss. mpg out of the motor.

In the UK on average, we are paying around £ 1.09 a litre for fuel (which = about $ 6.95 a US gallon)... (maybe I should have got a Bonneville!!, only joking).

Cheers
Steve

[roadbosstx]

You are the man, Steve Block! Thank you very much.