DOHC Plugs

[B4ndit]

Are there any Iridium plugs for the DOHC. I can only find NGK MAR8B-JDS and they seem expensive (Normal Iridium price for a standard plug) for standard plugs. Especially when you have to buy four.

NGK don't list them on their site. Any reason Iridiums don't show up for this bike?

 

[ghiribizzo]

Nope - there ain't any. I buy mine from Germany...

 

[Bendy toy]

My single cam is using the equivalent NGK plugs with ordinary single electrode. The fuel consumption hasn't changed and I saved a wedge on spark plug prices. We will see how long they last compared to posh plugs.

 

[birdseye]

Most bikes dont do enough mileage to really need a plug change at all often. Never change them in the cars in 60k miles so why do so in a bike? Adjust the gap ofcourse as erosion happens.

 

[B4ndit]

Most bikes dont do enough mileage to really need a plug change at all often. Never change them in the cars in 60k miles so why do so in a bike? Adjust the gap ofcourse as erosion happens.

I am going to change the plugs on the next service and then hopefully keep them for a few years.

The American GS owners seem to rave about the Brisk plugs.

http://www.ebay.co.uk/itm/4x-BMW-R1...76?pt=UK_Motorcycle_Parts&hash=item53fb355a2c

Do you really get an extra 5 BHP out of them.

 

[cookie]

Do you really get an extra 5 BHP out of them.

no.

..

 

[Steptoe]

Do you really get an extra 5 BHP out of them.

BMW would spend thousands and thousands to get 5 BHP out of an engine.

I'm sure they'd have simply used 4 spark plugs if they could

 

[sethmopp]

They also apparently have a very short service life.

 

[birdseye]

I am going to change the plugs on the next service and then hopefully keep them for a few years.

The American GS owners seem to rave about the Brisk plugs.

http://www.ebay.co.uk/itm/4x-BMW-R1...76?pt=UK_Motorcycle_Parts&hash=item53fb355a2c

Do you really get an extra 5 BHP out of them.

Even if you did get 5 more, you wouldnt notice it or even use it much

 

[Bendy toy]

5bhp extra in a 1200GS is about 5% which I would notice at the fuel pump. More power = less fuel used - generally anyway.

Plugs do wear and need to withstand many millions of very hot sparks burning away at the electrodes, but the basic job is simple. Worn plugs are not reliable, but once the fuel mixture has caught fire, the plug has nothing more to do until the next firing stoke.

Plugs that claim a significant power increase are snake oil. Ask for the supplier's research proof and watch them wriggle.