Spark Plugs - All 4

[mad1150]

I know the Autolite AP3923 is good for the Primary, but is the AP4164 correct for the secondary? And does Wal-Mart have the 4164's. (I have to ask, because since they're nearly all Super-Marts now, I save more money at Wal-Mart than any other store I go to because I usually walk out empty handed and head to Ace, Lowes, Auto-Zone, etc. )

I also found a post by Dr Strangelove that said the 4164's don't fit the OEM SP wrench, so what SP socket do I need for 4164's ?

[Dr. Strangelove]

I didn't see the 4164's at walmart, but they had them at Advance auto and they were cheap--they even had the platinum flavor. I was a little surprised to see the AP's there because the selection was much slimmer than I anticipated. I don't know if the AP4164's have the same diameter as the non platinums; but the 3923's fit the OEM sp wrench just fine.

I, too, would like to know what socket to use--that is a tight spot. I reused the Bosches that were in there and incorrectly gapped--too close--I just cleaned and regapped.

John

[adg44]

I used a Husky spark plug socket to change mine out, the craftsman one I had was a bit too thick. The factory one works, but you can't stick it on a torque wrench!

I changed my plugs with NGK Iridiums, and NGKs are really the only spark pluge I'll use. I went one heat range warmer on the lower plug, and things seem great thus far.

- Anthony

[towerworker]

All that I have read says the 4164 is the correct secondary plug. I have a full set sitting here to at some point replace but have not done it yet so I can't comment on the correct wrench.
I bought my plugs at Advance Auto. All 4 plugs were under $10.

Wayne

[Dr. Strangelove]

I used a Husky spark plug socket to change mine out, the craftsman one I had was a bit too thick. The factory one works, but you can't stick it on a torque wrench!

I changed my plugs with NGK Iridiums, and NGKs are really the only spark pluge I'll use. I went one heat range warmer on the lower plug, and things seem great thus far.

- Anthony

Yes, the bosches that were in there fit the oem wrench, too. It was the 4164's that were too wide for the wrench. So I gapped them, correctly, and cleaned and reinstalled. I have the 4164's sitting patiently on a shelf.

[boxermania]

adg44

NGK's are good plugs, however, I'm a bit surprised that you chose a heat range hotter for the bottom plug than the factory recomendation, specially since the Boxer is air cooled and runs, by definition, hotter than a water cooled engine.

Mind you that hot and cold plugs have their use......a hotter plug does well in slow city riding to keep the deposits and carbon off the plug, but not as well at high sustained speeds.

Have you thrown in a new set of plugs took a ride and read them? and that lead you to the hotter plug? What made you do it?

[adg44]

adg44

NGK's are good plugs, however, I'm a bit surprised that you chose a heat range hotter for the bottom plug than the factory recomendation, specially since the Boxer is air cooled and runs, by definition, hotter than a water cooled engine.

Mind you that hot and cold plugs have their use......a hotter plug does well in slow city riding to keep the deposits and carbon off the plug, but not as well at high sustained speeds.

Have you thrown in a new set of plugs took a ride and read them? and that lead you to the hotter plug? What made you do it?

When I was looking for plugs I did a lot of reading on this forum about what people are using. It seems that many, many people are using one range hotter plug for the bottom plug, so it matches that of the top plug.

When I pulled my old plugs from the bike, the top ones look good, but the bottom ones were completely fouled and covered in oil. That told me that it wouldn't be a bad idea to go one range hotter and match the top plug. I've done only about 400 miles since then, but the bike has been running flawlessly and it seems to have considerably more power.

I used these plugs:
Top: NGK BKR7EIX (2667)
Bottom: NGK DCPR7EIX (6046)

A plug with a heat range of "7" is still a cold plug according to NGK. The OEM Bosch plug was "YR6LDE", which has a heat range of 6, but that is equivalent to a heat range of 8 on an NGK plug. You think they would standardize this stuff or something!

*EDIT*

Looking at this chart:



It seems that the Bosch plug is pretty similar to a heat range of 7 with NGK, and not 8. Seems like not much changed afterall...

- Anthony