Hi guys, I am probably opening up a can of worms here but does anyone recommend a spark plug other than standard. I think Bosch X5DC are the norm and the ones I have in are XR5DC and while I am aware the main difference is the "R" is for suppression of excess electrical noise is there any noticeable difference in performance as the originals are a bit hard to find.

Regards,

Phil Mars

Hi Phil,
I am a fan of Denso Iridium plugs for two reasons they have a very small electrode making it fire more readily and they are very durable. I run them in both AMG Mercs and in the Volvo 245 so from the sublime to the ridiculous. I am about to order a set for the K Bike.
Regards,
K-BIKE

The Bosch XR5DC are for the 4 valves K engines and the X5DC are for 2 the valves.
XR5DC : R = denotes a resistor spark plug.

I cannot find anymore the X5DC (apparently Bosch stopped the production ???) and I replace them by NGK D7EA. I believe that NipponDenso X22ES-U will work on 2 valves K bikes.

Here is a chart for Bosch plugs and the meaning of letters and #

Bert

These are the model, year and gap recommendations from the Denso website http://www.densoiridium.com/find_part.php?tab=2
Regards,
K-BIKE

1988 BMW K100 1,000 cc IX24B 0.035
1991 BMW K100 K1 1,000 cc IX24 0.020
1992 BMW K100, K100RS 1,000 cc IX22B 0.035
1991 BMW K100, K100RS, K100LT 1,000 cc IX22B 0.035
1988 BMW K100LT, K100RS, K100RT 1,000 cc IX24 0.028
1989 BMW K100LT, RS 1,000 cc IX22B 0.035
1988 BMW K100LT, RS, RT 1,000 cc IX24B 0.035
1992 BMW K1100LT 1,100 cc IX22B 0.035
1997-1994 BMW K1100LT 1,100 cc IX22 0.024
1995 BMW K1100LT, K1100R, K1100 1,100 cc IX22B 0.035
1994 BMW K1100LT, K1100RS 1,100 cc IX22B 0.035
1996 BMW K1100LT, RS 1,100 cc IX22B 0.035
1997-1994 BMW K1100RS 1,100 cc IX22 0.024
2003 BMW K1200GT 4-stroke 1,171 cc IW27 0.028
2003-1999 BMW K1200LT 4-stroke 1,171 cc IW27 0.028
1998-1997 BMW K1200RS 1,200 cc IK20 0.032
2003-2000 BMW K1200RS 4-stroke 1,171 cc IW27 0.028
1994, 1992-1991 BMW K75, K75RT, K75S 750 cc IX22B 0.035

Thanks for that info and I was probably aiming towards the NGK plugs and had forgotten about the Iridium or assumed they would not have one to suit but the Denso site is quite comprehensive in the models they support. I am also showing my age as I remember when the "U-Groove" was introduced as the greatest thing since sliced bread. I also notice that NGK has an Iridium plug and found another site recommending a double Iridium plug. So plenty of food for thought.

Regards,

Phil

Please.....
what is the other site recommending the double iridium plug ?

Thanks

Bert

Hi Bert the website is : http://purchasenet.com.au/shopping/double-iridium-sparks-plugs-p-30.html and once again sound like the greatest. The catalogue only specified cars although just about every make and model, and from memory there are some parts on the K series engine similar to the early 3 series car so their may be one suitable.

Regards,

Phil

Hello to everyone,

Last week i have changed the spark plugs of K100RS!

After talk with some friends and my mechanic i choose the NGK Iridium DR7EIX.

I have already make some kms, and i like them. I also note a little decrease in fuel consumption!

Have anyone also test it?

Good curves

yes the ngk iridiums work well ... have been useing the platinum versions of them for years and lately have tried the iridium versions since i changed the coil for a higher energy output and slightly bigger gap.. (not bmw application )...(nice result by the way). they are on my list of must haves ....as soon as i get rich and other issues have been resolved on the k.

I'm trying to sort out a minor but irritating problem which has made me look up advice on plugs.
Since it went back on the road it has been slightly harder to start, tickover is lumpy and its a bit of a pig in traffic.
Checked coil connections and looked for sparks or clicking noises at the plugs. All okay.
Started to wonder about the new Bosch plugs I installed.
Correct grade but read recently about someone else who had similar problems with a new set of Bosch plugs.
Bert had said that they were out of production but these were made in Brazil. No offence to any Brazilians reading this but I assumed Bosch plugs would have been made in Germany.
Going to try a set of NGK's to see if it helps.
Wasn't doing this before and have shimmed valves, synchronized injectors, new air & fuel filters and new fuel pump.
Performance is fine above 1000-1200 rpm otherwise.

Perso NGK DR8ES L

john ....lots of plugs these days come without the ferule ...leaving only the threaded section at the top of the plug ..

the plug tops are set up for the ferule to be there .

i trust this is the case with your bike as i found that my old plugs had been installed without them . since replacing mine ( merry chase to find ferules ) the bike starts and runs like a dream .

Hi there, Ive been using champion RA8HC for the last 14000km with no problems and excelent results.
Best regards
JAP

Hi Charlie. If only it had been that simple.
The Bosch plugs came with them attached.

Thanks JAP. Rarely see Champions here now.

Comberjohn wrote:Hi Charlie. If only it had been that simple.
The Bosch plugs came with them attached.

oh well ! there have been some excelent sugestions for options here john , hope you get your "pig" back to normal soon huh ?

my car runs woefully on the "standard" lowgrade fuel we get out here, is verry poor performance up to about 2.5k . so i use the highest grade whenever i can , have you tried the shell high grade john ?

Fuel is bad enough at $10 a gallon here.
Still think its a bad plug. Won't know for sure until I swap them.

I am using NGK D8EA with good results. I've left them in there for at least 30,000 kms and in Australia's 'generally' warmer climate this slightly 'colder' sparkie has no ill effect on the engine's performance or fuel mileage. A bike mechanic in Perth WA once told me in no uncertain terms that the cross reference from Bosch X5DC to NGK had to be NGK's '8' range and not the '7' that some use. I have not verified that information. Someone's pinched my NGK book!

(Update) Everything I read online suggests the '7' range is suitable for 8V and 16V K100 models, as you know. I want to add that the '8' range last a very long time for me in my bike, in the Aussie heat, don't load up and the bike performs as well as when I once used the D7EA. I did notice a slightly better fuel mileage figure overall with the D8EA plugs, but this can be influenced by a whole host of other conditions. I will stay with the '8' for now.

I'm using the D7EA with good results.
Have a look what you need/want; the 'R' stands for resistor. The first bikes had resistors in the cap and lines so can do with a D7 (or D8 if you like). Newer bikes will need a DR7 as those leads/caps are fitted without resistors.

Yes, this is true, the 'R' is for resistor. I am not using OEM ignition leads any longer, but instead have a way-cool (blue in colour, Blakey!) custom set fitted without the 5K ohm caps. They work a charm.

Two Wheels Better wrote:Yes, this is true, the 'R' is for resistor. I am not using OEM ignition leads any longer, but instead have a way-cool (blue in colour, Blakey!) custom set fitted without the 5K ohm caps. They work a charm.

TWB, are these leads a specific K set or made up, a lot of folk trade up to silicone leads as its said they last longer and do not break down with age as copper core ones, not yet tried them my self so cannot comment.

BIG D

Big D, I went to the local parts shop and bought some 8mm silicone leads in the correct lengths (as equal in length as I could get but still have room for them all to fit) with a 90 degree elbow at the spark plug end. They're slick, cheap, fall into the 'correct' resistance range, and readily available. I have to say that although my OEM leads each registered as fair to ok according to my ohm metre the replacement leads show a marked improvement in smoothness and rev-ability. I'm happy, and it cost me less than $30 skins.

Thanks TWB, thats the info I was looking for I will give them a bash when I change plugs soon.

BIG D

TWB
Did you use the original metal caps or aftermarket ones?
Having seen some of the prices for some K leads, ( ouch! are they gold cored??)
I reckon I'll be nipping down the local automart for mine too
when I need em