|New plug in the middle
Well... those days are gone... for the most part. We don't have distributors (no cap or rotor) and many engines don't even have spark plug wires - they just place the coil on top of the spark plug. But the spark plugs are still a main part of our engines. Sometimes I think spark plugs are the forgotten step child of the engine maintenance procedures. People know about changing oil and filters but the spark plugs are left for last or totally forgotten. Many of my car driving friends never change the plugs until something happens. Recently one of my friends said "I just changed the plugs and three coils on the Ford".
I'm one of those guys that "forgot" to change the sparks plugs on my 2010 RT. I have a couple of excuses but that doesn't matter now (although I wonder why they were never changed at my dealer/mechanic provided services). The fact is that I rode my bike for 32,000 miles on the original set of plugs. I guess one advantage of dual plugs on the recent BMW boxer engines is that we can milk the plugs to the very end. The bike ran fine but look at the pictures above and below. You can see the center and side electrodes severely worn. The wire gauge I just used to measure the gap only goes up to 0.040 of an inch and it still had plenty of room left. At least 50% more gap.
|My idea on how they should be built
For $25 I think we should get the configuration shown above. Of course that means our spark plug companies won't sell nearly as many spark plugs as they do now. Look at some of the high end auto spark plugs and you see very well designed electrodes. The edges, if there are any, are not the closest point to the center electrode. The main objective is to be equidistant at all points.
Anyway, back to my bike. It feels like it's running better but it could be a placebo effect since I changed the spark plugs myself and feel like I did a wonderful job. In the future I'm changing the plugs as recommended by BMW or at the least every 20K miles.
Now at 38,000 miles I think I better change the alternator belt. I already have it - just need to do the work.