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What a Numpty!

Posted: Sun Feb 22, 2015 2:56 am
by Shakey
In Scotland, a Numpty is a foolish person.

So for reasons too many to bore you with, I haven't been able to get out on a ride since October last year and I hate starting my bikes after a long lay-up as the metalwork will be moving without lubrication for a few seconds. I well remember the noises an old FJR1300 of mine made in this situation.

A plan was needed. I'd purchase a coil puller tool, remove the coils and then turn the engine over on the battery to circulate some oil.

Having removed the cylinder head protectors (BMW ones) and figured out the best way to prise out the rubber coil covers, I set about removing the coils. They came off very sweetly and I carefully arranged each one suspended below the bike. Now I'm ready to turn over the engine.

The more astute and experienced reader will know straightaway what happened when I hit the starter.............. The bike burst into life immediately and ran very sweetly indeed.

There can be only one conclusion here I thought to myself. Either my bike is possessed by benificent demons or there's more than one spark plug per cylinder :-k

Turns out I already knew that so lets call it a senior moment eh? :lol:

The bike ran beautifully on the secondary so it beats me why BMW felt they needed two plugs :?:

Can anyone enlighten this Numpty?

Re: What a Numpty!

Posted: Sun Feb 22, 2015 10:15 am
by MTBeemer
The second spark plug in each cylinder improves the uniformity of combustion and greatly reduces the occurrence of the surging that was an issue in some oilhead bikes.