Spark plugs - multiple questions

[challey]

I will soon be ready to do a major service to my '03 single spark R in preparation for riding to the International Rally and want to change the plugs as part of the job.

The stock plug on the single-spark R is the NGK BKR7EKC, which is a dual ground electrode plug with a 19mm reach. NGK shows the BKR7EIX as the irridium alternative but this is a single electrode plug. Though it has the same 19mm reach, looks like it may be longer overall. Is it really longer and does it (or any single electrode plug) risk reaching too deeply into the cylinder and being hit by the piston? What is the advantage of an irridium plug?

While I don't have any complaints about the NGKs, they are difficult to find except from the dealer. Autolite and Champion are easy to come by, but neither the 3923 nor the RC9YC appear to very highly regarded by the R community.

That leaves ND and Bosch. Denso shows the IK22 as the stock NGK equivalent. Anyone have any history with the ND? I don't know what the Bosch equivalent is - has anyone used these?

Charlie

[Loree]

How do you know you have a single spark plug? I have an 02 - what type of plug does it have? I don't have the OEM manual for the bike, else I'd look there.

[BigC]

http://www.ngk.com/ is a good source. Irridiums last longer and maybe a hotter spark? I replaced both of my stockers with irridiums. This was the post I used as reference: http://www.r1150r.org/board/viewtopic.p ... highlight=
That may be for twin spark models though...which would be the '04's and up Loree.

If you pull your stockers, prepare for a shock if your in the less than 10k mile range...they'll be ugly. I'm hoping that when mines broken in, the build up will significantly be reduced. Seafoam is your friend, lol.

[towerworker]

I ordered the oem NGK plugs from Autozone for about $4 each. Took one day to get them.
Could probably get them from Advance as well.


Wayne

[def38]

I run Autolite plugs in my '01 R1150GS. I use the 3923s in winter and 3922s in summer (the 3922s are one heat range cooler). My experience is better idle and better cold starts. Also, the Autolites are $0.99 each. Don't bother with Iridium plugs....no benefit.

[challey]

How do you know you have a single spark plug?

I guess you could say it's a twin spark, it just has one plug in the left cylinder and one in the right . . .
Seriously though, I think BMW sold the '04 as the dual spark in the US, even though it was '03 for the rest of the world.

Towerworker: Thanks - I'll try my local Autozone to see if they'll order the NGKs.

And thanks for the advice about the Iridiums.

Charlie

[gregor]

Just fitted a pair of standard NGK BKR7EKC to my 2002, R1150R.
£12 ($24) the pair including p&p from a dealer. Rather expensive I agree but the bike runs a lot smoother now after the original plugs being untouched from new.

[def38]

Irridiums last longer and maybe a hotter spark?

Spark temperature comes from the voltage (coil) and gap. Iridium and platinum are noble metals that tolerate high temperatures without degrading. While both are useful in sparkplugs, the price difference is difficult to justify in road machines. Leave the high dollar plugs for those who race.

[CycleRob]

If the cost doesn't hurt you I'd go with the Denso IK22 plugs as they'll last the longest and they posses a wider heat range than non precious metal plugs do. On the downside, they are many times the cost of the conventional Autolite 3923 from Wal*Mart. A wider heat range means that both a slow cruise or extended full throttle can be safe;y handled by the Denso IK22 plugs.

[challey]

Thanks Cycle Rob.
Cost is not really the issue, it's more the availability. Though my local auto parts mega store doesn't stock either NGK or Denso, I think they can order either.
Am I correct in assuming you think the Denso is superior to the NGK?

[CycleRob]

It's not the mfgr, it's what it's made of. Platinum or Iridium are the best sparkplugs because the center electrodes both do not erode over time and the precious metals superior heat conduction means they will both have wider heat ranges than conventional sparkplugs.

[Paul Mihalka]

I used the Autolite 3923 in my '99 R1100RT for about 170K miles and in the '02 R1150R for 70K miles. I found they improve idle and less or no surging compared to the stock plugs. I gapped them new at 0.040 which is the max. BMW allows. I replaced them at about every 20K. Gap did not vary much and they always looked good.

[challey]

As it turns out, none of the autoparts stores in my area will order either NGK or ND plugs; however I am able to get Bosch.

Is anyone familar with the 4417? It appears to cross reference to both the BKR7EKC & the IK22, is a 4 gnd electrode design w/platinum tip and available for about $6.

Any help appreciated.

Charlie

[def38]

I used the Autolite 3923 in my '99 R1100RT for about 170K miles and in the '02 R1150R for 70K miles. I found they improve idle and less or no surging compared to the stock plugs. I gapped them new at 0.040 which is the max. BMW allows. I replaced them at about every 20K. Gap did not vary much and they always looked good.

Take Paul's advice here.....use the Autolites. Spend the big bucks on some flowers for your wife...better value!