Plug wire replacement

[montmil]

During my recent preview and purchase of my new/old 1981 R65, the seller told me that the left cylinder seemed to be reluctant to fire until, "the engine was well warmed." Huh?

During the warm-up period, I noticed the left cylinder would not fire at all, then it would backfire a bit, plus lots of rich, black smoke out of the LS-style black muffler. Eventually it all came together. Somethin' ain't right...

Purchase price offered continued to drop...

Bought the bike and took it to my son's shop on the south side of Austin. Later at my leisure, and with a cold one in hand, I chased the left spark plug lead and noted that it was draped over the top of the engine case. Further investigation turned up what appeared to be a small electric arc burn on the engine case fin where the plug wire was laying. Hum... You've already guessed, right?

I moved the wire off the engine case, turned on the key, touched the starter button and both cylinders lit off then settled into the classic BMW idle. To quote a famous Hannibal - not Lector -" I love it when a plan comes together."

OK. Got a weak spark wire lead. Recommendations for replacement plug wires? Are the ones I see on eBay any good? Other sources? Do I have to keep the galvanized metal plug caps? Yuck.

What's your experience? Remember, my personal intro mentioned I'd have questions. I want to keep you folks busy. Gracias.

Monte

[Rob Valdez 79 R65]

[size=14]This is for the wires and caps.  You could also have other issues.[/size]

I hate to sound like a broken record, but if it isn't the coil (although highly suspect, if original), then I have to ask, do you have the spark plug caps with the metal shield on them?  That is what originally came on my '79, and I tried to keep it original, but not riding in the rain forced me to NGK caps...

The following is kind of a trademark posting with me:



http://www.mikesxs.com/mikesxs-electrical.php?category_id=2.1

Scroll down.

I like the 5K cap on my points ignition (Part #23-3113).  I have been using them for about 15 years now (renewed every 2nd or 3rd year cause they are cheap).

He also has wire you need, in slightly longer than needed length.  

$11 plus shipping for all.

If and when you replace your wires, check the ends that come out of the coils.  If they are SOLDERED ON, that is good.  DO NOT THROW THEM AWAY!  You can use your soldering gun and pliers to remove them to use for your new wires.  They are much superior to the crimp-on type connectors.  Also save the rubber boots that cover the coil end of the wires.  I suppose auto parts stores would have them?

[Bob_Roller]

While you are replacing the ignition leads, take a real good look at your ignition coil.

If you have a grey and black coil, look it over good for cracks, it's commonly referred to as the 'crack-o-matic coil', if you have a red case coil, it's the later upgraded part, not as problematic as the original OEM coil.

[MrRiden]

Rob has a good source there! The main thing to keep in mind is that you need to pair a non resistor plug [I like the Autolite 64 plug] with a resistor cap [5K ohm for electronic ignition 1K ohm for points ignition] there is a lot of information on this if you have unlimited time and a high tolerance for extraneous personal reference, weird font combinations and excessive use of Highlighter and color here
http://bmwmotorcycletech.info/sparkplugs.htm
you've been warned!
rich

[Justin B.]

Rob has it right about the coil and NGK caps.  You can't get much better than the NGK caps unless, I suppose, you go for the ones they make for jet-skis - totally waterproof.  But, the standard ones look pretty waterproof to me.  As far as the actual wire goes, I would imagine any stranded solid wire core cable would be OK, you do NOT want to use a resistance core wire.  I suppose, though, that the spiral core supression wire (ala Taylor, MSD, etc.) would also work fine but would kinda be overkill.  

I have read anecdotal evidence that running too low resistance in the spark plug circuit can actually fry the hall-sensor in the bean-can.  Don't know how this would go all the way back and affect the trigger but "experts" swear it's so and I'm too cheap to argue with them and test the theory so I always use the resistor caps.  I suppose resistor wire would be OK with non-resistor caps as long as the resistance of the wire worked out to about 5 k-ohms.

I have a good stock of caps and wires on-hand as I had once thought about putting together a "kit" to sell on flea-bay but just never got motivated enough to do it...

Oh, if you do some searching here you should find some pics I posted of a 1982 "crack-o-matic"...

[nhmaf]

Yup, my pics from the "darkness that lurks beneath the tank" thread also has pics of a 1982 coil, with cracks in the surface - no burn holes though.
I am still running the metal cap BMW plug leads, but plan to switch to NGK resistor caps and appropriate plugs sometime this year - I've had very good success with NGK on all the Japanese machines I've owned over the past several decades...

There are plugs leads available on ebay but the source Rob points out is cheaper, and I don't think there is any difference in quality, but don't have personal experience to back that up (yet) !

[Rob Valdez 79 R65]

I have been using the caps (and wires) from Mike's XS website for at least 4 years, maybe 6.  I will have to check my receipts...

I also could be running 10k ohm resistance (on a points ignition) as I don't know if my spark plugs are non-resistor, or not.  I just buy the BP7ES as recommended by NGK.

NGK has a nice tech page(s), but I could find nothing relating to internal resistance.

[stevie]

Sorrry to gatecrash this thread guys. But I see the NGK caps that Rob recommends are meant to be for electronic ignition, does this not matter then for models like my 1980 which runs points  and condensor? Just curious as I think this may be one of my next jobs.

Thanks as always Steve.

[Bob_Roller]

The description of the 5k caps says it can be used with all electronic systems, not just electronic type systems.

The ignition leads and plugs are a little different than automotive useage, the wires are non resistor, the caps are 5k in resistance, and the plugs are non-resistor type.

Most cars and trucks use non-resistor leads and caps, and resistor plugs.

The Yamaha XS650 had points ignition up to around '80 or '81, just like the R65.

Most of the aftermarket pre-made ignition leads for BMW airhead bikes, come with these NGK caps.

[Rob Valdez 79 R65]

Sorrry to gatecrash this thread guys. But I see the NGK caps that Rob recommends are meant to be for electronic ignition, does this not matter then for models like my 1980 which runs points  and condensor? Just curious as I think this may be one of my next jobs.

Thanks as always Steve.

Steve, reread my post.  I am using the 5K caps on my '79, which STILL HAS POINTS.

It runs well.

[Ed Miller]

Steve, 1K caps are recommended for your points bike, but it should run fine with the 5K as well.  I think the trouble is the NGK 1K caps make you use the little silver nut thingy (sorry for the technical term) that goes on the threaded end of the spark plug, whilst the 5K caps do not use that.  I prefer to not use that nut, but for now on my only points bike I do.  I use the 5K on my R65.

I wish NGK made 1K caps that do not use the nut.  I bet they don't care what I wish.

[Justin B.]

To be honest, if you have a points type ignition you can run a straight non-resistor cap, unless you are trying to listen to an AM radio...  I would be very tempted to make up a set out of Taylor Spiro-Pro wire, now that would be trick...

[Rob Valdez 79 R65]

To answer anyone's questions about WHY I repeatedly buy the 5K ohm caps,
I like the fitting to the sparkplugs' threaded terminal better than the solid terminals.   Just a "thing" with me.



NGK Resistor Spark Plug Cap (5K Ohms). This Factory Original XS650 type
can be used with All electronic ignitions (spark plugs with threaded stud type
terminal end).


NGK Resistor Spark Plug Cap (1K Ohms) for use with Champion projected
nose Resistor spark plugs (with Solid terminal end). This Cap can be used with
Factory electronic or point type ignitions (spark plugs with threaded on or solid
terminal end only).


This is the only NON-resistor cap that Mike's offers.  I don't like it because I[/i] don't think it looks as nice...

Non-Resistor NGK Spark Plug Cap. Fits to spark plugs with threaded stud
type terminal end. Recommended for Early model 650's (points ignition).



All of the above is stolen from Mike's XS

[stevie]

Ok guys thanks for the info. As you have probably guessed I am somewhat electrically challenged. Moving on to the leads, there is some 7mm copper cored cable available locally would this be OK?. As always many thanks Steve.

[Bob_Roller]

That wire should work fine.

Just curious where you're getting the ignition wire from, some members have difficulty finding any locally .