Spark plugs for '04 K1200GT

[gregfeeler]

Interesting. So, how would you think those differences in heat range for the Bosch and NGK plugs would affect performance, in our Flying Brick engines? Given your sense of the NGK plugs being 'a quarter step off' the Bosch plugs, which would give better performance, i.e, ability to deliver strong, repeatable spark, under heavy load or sustained high-RPM operation? From the way you said it, I took it to mean that the Bosch plugs were slightly better. But it might be hard to generalize about this... and maybe we're getting off into the weeds here!

To be clear, I never said I've seen differences between Bosch and NGK plugs for classic K-bikes - only that I've seen some differences between different "equivalent" plugs occasionally over many years of working on engines. I've never used NGK plugs in any of my K-bikes (I have/had seven) because I've always found the Bosch plugs at a good price. IF there is a difference, I wouldn't expect it to be of any significance for a classic K-bike.

 

[corey61]

The problem is that we are guessing here about these specific plugs. I'm sure with some research you can find the published heat ranges of the NGK and Bosch. Since this is the internet, I'm betting we can find someone who's motor blew up with fresh Bosch plugs and some guy whose engine has gone 250k miles with NGK plugs and haven't missed a beat. Sorry, I'm not trying to dismiss Mr. Feeler's past experiences.

Also, do you think each same model of the same plug runs at exactly the same temperature setpoint? I have no idea what the tolerance level for these are...

I think you're way in the weeds here (been there myself quite a few times), especially because there's going to be a number of people who are going to buy the NGK plugs (or have them installed at the dealer) without sitting on a forum for 3 days researching the difference.

Your points are all very valid...! And I agree that I'm off in the weeds and it's starting to feel like a discussion of how many angels can dance on the head of a pin. So I'm good with wrapping up the discussion.

I do want to say one thing, though: my drilling down (e.g., with Greg Feeler) is actually an indication for my respect of the deep knowledge base that resides in MOA members and gets communicated (sometimes!) in these forums. I'm a very highly trained engineer but I don't have decades of experience tearing down motorcycles, rebuilding or modifying them. I just like to ride 'em!

So... I have deep respect for those of you who DO have that experience, and in the past I've asked some detailed questions (particularly when wrenching on my K12 and getting stuck) on these forums and been truly amazed at the depth of knowledge/experience that emerges in response.

My tendency - for good or bad - is to drill down to 'mine' any nuggets of such deep information. It's what I've done for a living for 30 years as an engineer and technology executive in high tech companies. Sorta comes naturally, at this point...

I do hope this approach doesn't seem pesky or petty. It's an attempt to wring out that deep knowledge carried by MOA members and again, if I didn't believe it's out there among our ranks I wouldn't bother with the follow-up questions. It's in no way meant to challenge people or grandstand about some trivial point. And yes, I'm aware... it can start to seem that way.

Thanks, all, for bearing with me and coming along for the ride. I'm bringing this particular ride back into the barn. It was useful to me and I appreciate all the back-and forth!

Time for a beer...

 

[corey61]

To be clear, I never said I've seen differences between Bosch and NGK plugs for classic K-bikes - only that I've seen some differences between different "equivalent" plugs occasionally over many years of working on engines. I've never used NGK plugs in any of my K-bikes (I have/had seven) because I've always found the Bosch plugs at a good price. IF there is a difference, I wouldn't expect it to be of any significance for a classic K-bike.

Got it, Greg... and thanks! I'm good with leaving it at that and I appreciate you taking the time to elaborate/clarify.

Cheers.

 

[gregfeeler]

Got it, Greg... and thanks! I'm good with leaving it at that and I appreciate you taking the time to elaborate/clarify.

Cheers.

No problem! I think one of the greatest values of this Forum is these chances to ask interesting questions and share information between people with very different backgrounds. You never know what someone will say in passing which will be valuable to you. I solved a problem with the battery in my K1200RS draining while parked to a parasitic power draw after a comment about an unrelated topic caused me to check the power draw of the Garmin power adapter when the GPS was off. Turns out that there was enough to kill my battery in a week or less.